Aging process of horror movie props?

[Humdizzy]

I was wondering if anyone knows the process that things like wardrobe and weapons go through in horror movies to get the way they look in the movies. I was on a couple sites that said that each prop in a movie is hand crafted to look the way it looks.

For halloween I want to be leatherface and I want to turn a brand new dress shirt, slacks, shoes, butchers apron, and chainsaw into pieces of crap without actually making them pieces of crap.