here's some moveset advice for poison Sapphire (it is sapphire right?):
tenta: Surf, Ice Beam, Barrier, Toxic/Giga Drain/Hydro Pump
crobat: Fly, Shadow Ball, Confuse Ray, Return/Sludge Bomb
muk: Sludge Bomb, Brick Break, Acid Armor, Return/Screech
vileplume: Sunny Day, Solarbeam, Sleep Powder, Giga Drain/Sludge Bomb/Acid
seviper: flamethrower, EQ, Crunch, Glare/Sludge Bomb
muk learns sludge bomb by level up (47), so dont use the tm on him.
also, get some ziggys for pickup abuse if you haven't already.