Not trying to be cantankerous, but I have to say the moldable shoe strikes me as way over the top. I go try on and buy a pair of shoes. If it feels good off the bike, it feels good on the bike. Now even if you think you need to mold your shoes because they are not perfectly to your liking from the store, why do you have to keep redoing it after riding with them? I stand behind the what feels good off the bike should feel good on the bike idea.

But having said all that, carbon paste is likely the answer to your problem.