Ocelot,

How about straight Shea Butter? 100% cold-pressed wildcrafted karite butter with natural vitamin E? I have very sensitive skin and I find that this is really the only cream that doesn't cause a reaction. I get mine from Terressentials (http://www.terressentials.com) - they make and sell natural and organic personal care products. (if the opportunity comes up, please tell Diana at Terressentials that Joyce from Aptos says hello!)

Your arnica gel idea sounds intriguing - I will have to give it a try if/when an actual sore appears. For me, the shea butter has done wonders for mild chafing.

Good luck!

-j