Thanks to Dawn for this Frugal Baby Tip!
For rash I use breastmilk. I just squirt it on at every diaper change when my son has a rash, and it is usually gone in a day. You don't have to rub it on, so no touching. Also, instead of wiping him, I rinse his bottom in the sink with cool water.
Breast milk is antibacterial, and has all those wonderful antibodies in it. So it just makes sense that it works so well. And it won't leave buildup on your diapers.