Hey if you want a rapid spinner for Ferrothorn, try a Tentacruel with Liquid Ooze. Also sets Toxic Spikes. Also covers Ice.
Tentacruel @ Black Sludge
Ability: Liquid Ooze
EVs: 240 HP / 244 Def / 24 Spe
Bold Nature
- Rapid Spin
- Toxic Spikes
- Scald
- Knock Off/Sludge Bomb