You might want to try extra lenses at the end of your washing cycles, even after you finished off the cycles, because maybe all of the detergent is not coming out. That could also cause rashes on a little ones bum. Oatmeal baths really help, you can add some milk to the bath as well to help calm skin irritation.
I have read that making your own detergent, for most of the recipes that I have seen anyway, are not appropriate for cloth diapers because they they break down the fibers or they coat the diapers and make them leak or affect the absorbency.
Semi-Crunchy Hippie Lover to
My Hunting Hubby Nathaniel (11/14/2009)
SAHM to Evening Lucille
(6/30/10) and Lachlan James