Is the saddle sore/irritation from shaving or does it just happen to be in that area? I've had good luck treating saddle sores with acne cream. As for ingrown hairs and the like, I tend to just let nature take its course because it seems the more I do, the less comfortable I am on the bike. Granted, I don't really swim, so it's not a huge issue. When I do a bit of clean up, I make sure to soak in the tub for a bit first and then use a new razor.
I bought a product some time ago from Sephora's online site that was designed to treat ingrown hairs. You might do a search, although tea tree oil could work, too.
Live with intention. Walk to the edge. Listen hard. Practice wellness. Play with abandon. Laugh. Choose with no regret. Continue to learn. Appreciate your friends. Do what you love. Live as if this is all there is.
--Mary Anne Radmacher