Angie,
It sounds like your problem is friction while riding? So you are experiencing lots of chafing? Or is it more soft tissue soreness/bruising? If soreness, no chamois cream is going to help much....... you need to find either a saddle or better position on the one you have. If it's chafing, then a chamois creme could definitely help. As I said before, I like the Assos and, yes, it does still contain menthol - you don't want to put it on any open sores or you'll never forget that you did! Assos actually recommends that you rub it into the chamois, not on you, before riding. It lasts a long time but not all day. If I need it, I take a small container with me and when I stop to replenish liquids, use a restroom, whatever, I just do a quick re-application.
If you are in an aero position on a tri-bike, I would recommend tilting your saddle down just a bit in the front. That can take some of the pressure off. How wide is your saddle? Maybe you need one that is quite narrow so your legs are not rubbing as you pedal. Good luck!! It can be a long process to find what works best for you.
Time is a companion that goes with us on a journey. It reminds us to cherish each moment, because it will never come again. What we leave behind is not as important as how we have lived." Captain Jean Luc Picard