Has anyone tried these?

http://www.amazon.com/Foot-Pet.....038;sr=1-8

I was wondering if they might extend the comfort time of my strappy flat sandals. They only really hurt in one spot, and it only begins to hurt after a few hours of wear. If I could get that one spot to stop digging, I think I could wear them more frequently. I don't know if these really work or if it's just a gimmick.