Suggestions of spraying paint, latex or oil on a braking surface..... Holy God help us all. This is why private people shouldn't be allowed to work on certain systems...like brakes!
I don't care how many times you've gotten away with it. I've gotten away with stupid shit too but that doesn't mean it wasn't stupid dangerous shit. Brakes work by friction. Any foreign material reduces this friction. You share the road with other people. Mmmkay?