Well, it looks like the home remedy formula works. I've taken 3 long bike rides now wearing the shirts that have bothered me recently, and while wearing the formula there's no pain/sensitivity whatsoever when done.
So for anyone else out there who needs something and doesn't want to spend $10 or more for a 1.3 ounce size of the official stuff, I recommend mixing up 50% Zinc Oxide, 50% aloe hand lotion (contains Vitamin E) and applying that. Save some money.
I haven't tried this on any other spot, but I don't chaff or get sore anywhere else while running or biking.