So you walk into a store, give the sticks and Indian rub burn for several mins and then complain that they are garbage? Wow.. only on the internet.
Ok, now let me explain to you what you did. The rubber on the DS4 sticks are a coating, when you rubbed on the sticks for half an hour you heated that rubber up which caused it to separate and break down. It's a natural rubber, it's not something that you'd use on a car tire, but should hold up to above average use. What you did wasn't even above average use. You tried to break them and you succeed congrats!
Very underrated post.