HordEV Guide

This guide is about an EV training method much faster than Super Training. With it, you can train your whole team in a few minutes.
By using the move Sweet Scent in some routes, you have a 100% chance of getting a horde battle, meaning you can easily kill 5 Pokémon that give out EVs on the same stats with a multi-targeting move, such as surf or earthquake, and if you are using the EXP Share, all of your team benefits from it.
Furthermore, if your Pokémon has Pokérus and the suitable power item, you'll get 10 EVs for a single EV giving Pokémon, or 12 for a 2 EV giving Pokémon. So you could potentially get 50 or 60EVs on a stat, on each of your Pokémon.
Here's a list of hotspots, divided by stat.

HP

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Column 1
[th]Pokémon[/th][th]Locations[/th][th]Frequency[/th][th]EVs (horde)[/th][th]+Power Weight[/th][th]+Pokérus & Power Weight[/th]
[tr][td]Gulpin[/td][td]Route 5[/td][td]Common[/td][td]5[/td][td]25[/td][td]50[/td][/tr]
[tr][td]Whismur[/td][td]Connecting Cave[/td][td]Common[/td][td]5[/td][td]25[/td][td]50[/td][/tr]
[tr][td]Slowpoke[/td][td]Azure Bay[/td][td]Average[/td][td]5[/td][td]25[/td][td]50[/td][/tr]
[tr][td]Foongus[/td][td]Rts 15/16/20, Pokémon Village[/td][td]Average[/td][td]5[/td][td]25[/td][td]50[/td][/tr]
[tr][td]Lickitung[/td][td]Victory Road[/td][td]Rare[/td][td]10[/td][td]30[/td][td]60[/td][/tr]

Attack

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Column 1
[th]Pokémon[/th][th]Locations[/th][th]Frequency[/th][th]EVs (horde)[/th][th]+Power Bracer[/th][th]+Pokérus & Power Bracer[/th]
[tr][td]Scraggy[/td][td]Route 5[/td][td]Average[/td][td]5[/td][td]25[/td][td]50[/td][/tr]
[tr][td]Axew[/td][td]Connecting Cave[/td][td]Rare[/td][td]5[/td][td]25[/td][td]50[/td][/tr]
[tr][td]Bellsprout[/td][td]Route 14[/td][td]Common[/td][td]5[/td][td]25[/td][td]50[/td][/tr]
[tr][td]Ekans[/td][td]Route 14[/td][td]Rare[/td][td]5[/td][td]25[/td][td]50[/td][/tr]
[tr][td]Cubchoo[/td][td]Frost Cavern[/td][td]Average[/td][td]5[/td][td]25[/td][td]50[/td][/tr]
[tr][td]Larvitar (Y only)[/td][td]Terminus Cave[/td][td]Rare[/td][td]5[/td][td]25[/td][td]50[/td][/tr]
[tr][td]Scyther[/td][td]Route 21[/td][td]Rare[/td][td]5[/td][td]25[/td][td]50[/td][/tr]
[tr][td]Weepingbell[/td][td]Route 19[/td][td]Common[/td][td]10[/td][td]30[/td][td]60[/td][/tr]
[tr][td]Arbok[/td][td]Route 19[/td][td]Rare[/td][td]10[/td][td]30[/td][td]60[/td][/tr]
[tr][td]Trevenant[/td][td]Route 20[/td][td]Average[/td][td]10[/td][td]30[/td][td]60[/td][/tr]

Defense

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Column 1
[th]Pokémon[/th][th]Locations[/th][th]Frequency[/th][th]EVs (horde)[/th][th]+Power Belt[/th][th]+Pokérus & Power Belt[/th]
[tr][td]Nosepass[/td][td]Route 10[/td][td]Common[/td][td]5[/td][td]25[/td][td]50[/td][/tr]
[tr][td]Roggenrola[/td][td]Reflection Cave[/td][td]Average[/td][td]5[/td][td]25[/td][td]50[/td][/tr]
[tr][td]Exeggcute[/td][td]Azure Bay[/td][td]Rare[/td][td]5[/td][td]25[/td][td]50[/td][/tr]
[tr][td]Skorupi[/td][td]Route 14[/td][td]Average[/td][td]5[/td][td]25[/td][td]50[/td][/tr]
[tr][td]Klefki[/td][td]Routes 15/16[/td][td]Rare[/td][td]5[/td][td]25[/td][td]50[/td][/tr]
[tr][td]Aron (X only)[/td][td]Terminus Cave[/td][td]Rare[/td][td]5[/td][td]25[/td][td]50[/td][/tr]
[tr][td]Geodude[/td][td]Rt. 18, Term. Cv, Vic. Road[/td][td]Common[/td][td]5[/td][td]25[/td][td]50[/td][/tr]
[tr][td]Gligar[/td][td]Route 19[/td][td]Average[/td][td]5[/td][td]25[/td][td]50[/td][/tr]
[tr][td]Durant[/td][td]Rt. 18, Term. Cave[/td][td]Average[/td][td]10[/td][td]30[/td][td]60[/td][/tr]
[tr][td]Graveler[/td][td]Victory Road (2&3)[/td][td]Average[/td][td]10[/td][td]30[/td][td]60[/td][/tr]

Special Attack

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Column 1
[th]Pokémon[/th][th]Locations[/th][th]Frequency[/th][th]EVs (horde)[/th][th]+Power Lens[/th][th]+Pokérus & Power Lens[/th]
[tr][td]Psyduck[/td][td]Route 7[/td][td]Average[/td][td]5[/td][td]25[/td][td]50[/td][/tr]
[tr][td]Houndour (X only)[/td][td]Route 10[/td][td]Rare[/td][td]5[/td][td]25[/td][td]50[/td][/tr]
[tr][td]Mareep[/td][td]Route 12[/td][td]Average[/td][td]5[/td][td]25[/td][td]50[/td][/tr]
[tr][td]Vanillite[/td][td]Frost Cavern[/td][td]Common[/td][td]5[/td][td]25[/td][td]50[/td][/tr]
[tr][td]Smoochum[/td][td]Frost Cavern[/td][td]Rare[/td][td]5[/td][td]25[/td][td]50[/td][/tr]
[tr][td]Spinda[/td][td]Route 21[/td][td]Common[/td][td]5[/td][td]25[/td][td]50[/td][/tr]
[tr][td]Roselia[/td][td]Route 7[/td][td]Rare[/td][td]10[/td][td]30[/td][td]60[/td][/tr]

Special Defense

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Column 1
[th]Pokémon[/th][th]Locations[/th][th]Frequency[/th][th]EVs (horde)[/th][th]+Power Band[/th][th]+Pokérus & Power Band[/th]
[tr][td]Hoppip[/td][td]Route 7[/td][td]Common[/td][td]5[/td][td]25[/td][td]50[/td][/tr]
[tr][td]Mime Jr[/td][td]Reflection Cave[/td][td]Common[/td][td]5[/td][td]25[/td][td]50[/td][/tr]
[tr][td]Swablu[/td][td]Route 21[/td][td]Average[/td][td]5[/td][td]25[/td][td]50[/td][/tr]
[tr][td]Lombre[/td][td]Pokémon Village[/td][td]Rare[/td][td]10[/td][td]30[/td][td]60[/td][/tr]

Speed

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Column 1
[th]Pokémon[/th][th]Locations[/th][th]Frequency[/th][th]EVs (horde)[/th][th]+Power Anklet[/th][th]+Pokérus & Power Anklet[/th]
[tr][td]Minun/Plusle[/td][td]Route 5[/td][td]Rare[/td][td]5[/td][td]25[/td][td]50[/td][/tr]
[tr][td]Zubat[/td][td]Connection Cave[/td][td]Average[/td][td]5[/td][td]25[/td][td]50[/td][/tr]
[tr][td]Wingull[/td][td]Rts. 8/12, Azure Bay[/td][td]Common[/td][td]5[/td][td]25[/td][td]50[/td][/tr]
[tr][td]Taillow[/td][td]Route 8[/td][td]Rare[/td][td]5[/td][td]25[/td][td]50[/td][/tr]
[tr][td]Yanma[/td][td]Route 10[/td][td]Average[/td][td]5[/td][td]25[/td][td]50[/td][/tr]
[tr][td]Electrike (Y only)[/td][td]Route 10[/td][td]Rare[/td][td]5[/td][td]25[/td][td]50[/td][/tr]
[tr][td]Stunky[/td][td]Route 11[/td][td]Average[/td][td]5[/td][td]25[/td][td]50[/td][/tr]
[tr][td]Starly[/td][td]Route 11[/td][td]Rare[/td][td]5[/td][td]25[/td][td]50[/td][/tr]
[tr][td]Murkrow[/td][td]Rts. 15/16[/td][td]Common[/td][td]5[/td][td]25[/td][td]50[/td][/tr]
[tr][td]Poliwag[/td][td]The Pokémon Village[/td][td]Average[/td][td]5[/td][td]25[/td][td]50[/td][/tr]
[tr][td]Floatzel[/td][td]Victory Road (1&4)[/td][td]Average[/td][td]10[/td][td]30[/td][td]60[/td][/tr]

Mixed EVs Hordes- (This last part I was really lazy about)

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Seviper x4, Zangoose x1 (Y only) - 6Att, 4 SpA (12Att, 8 SpA with Pokerus, 24/16 with Pokerus and macho brace) - Average, Route 8

Zangoose x4, Seviper x1 (X only) - 9 Att, 1 SpA (18 Att, 2 SpA with Pokerus, 36/4 with Pokerus and macho brace)- Average, Route 8

Nidoran F x4, Nidoran M x1 (Y only) - 4 HP, 1 Att (8HP, 2Att with Pokerus, 16/4 with Pokerus and macho brace)- Route 11, Common

Nidoran M x4, Nidoran F x1 (X only) - 4 Att, 1 HP (8Att, 2HP with Pokerus, 16/4 with Pokerus and macho brace)- Route 11, Common

Roggenrola x4, Carbink x1 - 5Def, 1SpD (10Def, 2SpD with Pokerus, 20/4 with Pokerus and macho brace)- Reflection Cave, Rare

Tauros x4, Miltank x1 - 4 Att, 1 Def, 4 Spe (8Att, 2 Def, 8Spe with Pokerus, 16/4/16 with Pokerus and macho brace)- Route 12, Rare

Durant x4, Heatmor x1 - 8 Def, 2 SpA (16Def, 4SpA with Pokerus, 32/8 with Pokerus and macho brace)- Route 18, Rare

Trevenant x4, Sudowoodo x1 - 8 Atk, 2 Def (16Att, 4Def with Pokerus, 32/8 with Pokerus and macho brace)- Route 20, Rare

That's it! If you have any question or suggestion, feel free to ask me personally or on this thread. Remember, you have to use Sweet Scent for this to work!