Oven pride works mate, but I use caustic soda which is the agent in oven pride that does the stripping. You can get it from most chemist, b&q etc.
Just do it outside with gloves and googles and don't stand there breathing in the vapour!
my thread on polishing rims shows the process.
Less hassle is to take them to a powder coater and get them 'aqua blastered', they guy I use charges £10 for 2 rims - lot less bother but not as much fun!
Enjoy!