I had a similar 'epiphany' (sic?) when I tried scrubbing paint off my hands with a nail brush for 5 mins to no avail, but one quick wipe with a 'wet wipe' and the paint was gone!

I now use cammomile tea and a drop of tea tree oil in a small pump bottle and cloth wipes (I brought some but would be easy to make if you had an overlocker or brought some microfleece). My DD also had nasty nappy rash and this really helped to calm it. I've read that you do need to be careful with tea tree oil as some bubs can have a reaction so just make sure you use sparingly and watch for a reaction.