I don't think I've ever heard of it before, and now I'm curious. My commute isn't long enough for this, but I also do longer rides. Would it help keep my feet warm on long rides?
I guess Cyclocross racers use it to keep their legs warm during races, because legwarmers get soggy.
It might help on feet--but I always recommend wool layers of socks and warm shoes to keep toes warm. That's a body part you want to keep toasty. As far as I can tell, the burning sensation from the cream only helps keep you
feeling warmer.
And the previous commenter has a good point about DIY. I imagine after getting all the fragrance components I want, making it would be a little spendy, but it would be a fun project and gift!