Hibiclens. It's a great scrub, antimicrobial. Good for road rash or cleaning saddle sores. I then like to use an acne gel to help dry it.

I rarely get sores, and if I have any kind of raw rough skin down there after a ride, it's because I either forgot or did not apply enough shea butter or butt cream. The best saddle sore is the one you did not get- so look at the clothing, saddle and bike fit to minimize their appearances.