Strat only reasonable at (29+ / 12+ / 4+) IV Speed, aka 16+ at L12
Exactly (29-31/12/4-5) Speed IVs are a bit dicey, because you are speedtied with Zubat)

Riskier due to higher Supersonic chance on Museum Zubat

Rusturf Tunnel Menu:
Repel
Heal to full
Teach Echoed Voice over Mud Slap (Slot 4)

Pooch: Water Gun x3 (98.4% at 18 / 19 Sp. Atk ((25+ / 9+ / 0+))

Dewford Cave Menu:
Super Repel/Repel, heal if not in torrent, Equip Silk Scarf

Slateport Museum Fight 2:
Zubat: Tackle x2 (90.2% to 2HKO at (x/10-12/x) Attack IV, or 27 Attack)
Numel: Water Gun

Pre Rival 2 Menu:
Heal to a comfortable HP
Super Repel

Mauville Bike Menu:
Equip Soft Sand over Silk Scarf
Turn off Exp Share
Register Bike
Teach Bulldoze over Tackle (Slot 1)

Pre Rock Smash Menu: 
Teach Rock Smash over Echoed Voice (Slot 4)
Super Repel

Do Strength strats for Mt. Chimney