If a batchelor got tired of buying shampoo, toothpaste and shaving cream every so often and came across this amazing sale and decided to stock up with a multi-year supply, how long with these items stay good in a regular residential closet?
I dont have the exact answer, but I have used both shaving cream and shampoo that was at least 3-4 years old and it was fine.
I dont think any of those things can go bad per se, just become less effective.