Peaceable Projects Inc. is a U.S.-based non-profit group that brings the vast resources of the wide world together with the ongoing needs of the people who live, work, and travel on the Camino de Santiago pilgrim trail network in Spain.
I haven’t heard of PreHeels before. When I walked my caminos I applied Blue Steel anti-chafing cream (a “liquid powder”) each morning and managed to avoid any blisters. The key ingredient is dimethacone which incorporates into the epidermis and prevents friction against the dermis. Apparently it is this repetitive and prolonged friction which causes blisters. Many I met used Vaseline with similar outcomes but it was too greasy and messy for me.
Yes, boot lacing and tape are very helpful. After a couple caminoes and thousands of miles of wilderness backpacking that started back in the 60's, I think I pretty much know every preventative and treatment option in the blister world. This Pre-Heels thing was new to me. It's actually the opposite of skin softener, which is pretty much the last thing you would want. Rather, it provides a protective coating to reduce friction and hopefully minimize the sheer force which causes blisters. I just wondered if it works. The comments on the Amazon site were about 75% positive although I got the impression that it seemed to be most useful for women's high heels. With respect to general hiking and and gear matters, I'm always interested in "something new under the sun."
I think that's because it is being marketed to women in high heels. As @jayree mentioned, the active ingredient seems to be dimethicone, the same ingredient in other anti-friction preparations which are marketed to runners, hikers, etc.