Originally Posted by cvac
Germs are the least of your problems with used shoes. The real problem is the foot imprint and wear pattern developed by the previous owner. That can't be fixed without taking the shoe apart. It's not something that is fixed with recrafting or resoling a shoe either.
I've bought quite a few pairs of used shoes from SF now - admittedly, most were very lightly used - and I have not yet had a problem with the foot imprint/wear pattern of the previous owner.
The only shoe that felt a little funny was a pair of Ferragamo split-toe bluchers - that were fairly well worn and also very cheap - but after redoing the heel and wearing them a few times, they felt fine.