Eevee is Lax with 1/25/26/31/24/24 IVs
Manip 1026 Naughty Mudkip 
Brendan: Tackle Eevee twice, Water Gun Spearow Twice, finish Spearow turn 3
Calvin: Tackle + Water Gun Zigzagoon, Tackle + Water Gun Poochyena
Buy 2 X-Attacks and 3 Repels
Repel before Forest
Grunt: Tackle + Water Gun spam, Pooch first
Get Oran Berries and Scald, teach over Water Gun immediately
Double Fight: Tackle + Tackle x2 Lotad, Tackle + Scald spam Seedot 
Buy Ice Beam, leave shop interface
Teach Ice Beam over Tail Whip
Sell Ice Beam and Scald
Buy 3 Supers, 4 Potions, 4 Repels and TM24 Tbolt
Get Quick Claw
Rustboro Gym Trainers: Tail Whip + Scald spam
Optionals: Fight Gentleman, Bug Catcher, Top Youngster, both Hikers
Get XSpecial on the right route
Equip Oran Berries on both
Roxanne: Turn 1: Round Eyes Lileep & X Spec Mudkip
Turn 2: Round Eyes Lileep/Heal and Scald Geodude
Turn 3: Heal/Scald Lileep
Turn 4: Heal/Ice Beam Lileep
Turn 5: Heal/Ice Beam Nosepass
Turn 6: Heal/Scald Nosepass
Scald spam Omanyte
Okay if Eevee is dead, lost exp though
Mud Shot grunt if you have it
Go to Dewford, get all stones, use Thunderstone on Eevee and teach Tbolt over Tackle
Use 2 Repels, get Escape Rope and do Granite Cave and then leave
On Beach, fight 3 fights in house for 6 Soda Pops and 1 double outside
Fight Museum Grunts (Tbolt and Ice Beam Lombres, Scald + Tbolt 2nd fight)
Mud Shot + Quick Attack/Double Kick Plusle/Minun fight when you get there
Fight Delcatty/Persian and Plusle/Minun to left of Trick House (but not aroma lady) and spinner right before Rival 2
Return to Slateport
Sell all stones, Tbolt and Steel Wing
Buy 21 Supers
Repel, equip Quick Claw and Teach Rock Tomb over Tackle before rival
Rival 2: Turn 1: TBolt Vaporeon + Whatever
Turn 2: Heal hit poke + Tbolt Vaporeon
Turn 3: Scald + Tbolt Mightyena
Turn 4: Ice Beam + Tbolt Lombre
Turn 5: Rock Tomb Shedinja + Tbolt Taillow
Turn 6: Quick Claw proc Ice Beam + Tbolt or Tbolt para + Ice Beam
If neither, revive Marshtomp on slave and come back in
Double outside: Mud Shot Magnemite + Tbolt Abra
Scald + Tbolt Turn 2
Get Rock Smash, XSpeed, Bike, TM26 Earthquake
Teach Rock Smash over Rock Tomb, Earthquake over Mud Shotequip Bike, heal all to full, ether Tbolt, go fight right trainer
Deandre: Scald + Tbolt x3
Wally: Scald Larvitar + Tbolt Ralts
Ben: Scald + Tbolt x2
Wattson: X-Attack x2, X-Speed Marshtomp, EQ Spam
Repel 3 times on the way up
Get Nugget
Sell Nugget, EQ and Rock Tomb
Buy 15 Super Repels, 18 X-Specs, 11 X-Speeds, 15 X-Attacks