Well, I was going to suggest you stay away from dish washing soap/detergents because they can damage clear coats and paint on the surface of a car.
I was just thinking if you have rims that are painted/clear coated (factory or not) it could possibly damage that as well.
When I worked at a detail shop I learned the hard way that using really strong cleaning agents on rims is dangerous.
Some alloys can take just about anything, just fyi for anyone reading this, our stock rims do not count! haha
Also, if you clean them often, its even more a reason to use something light.