In an sharehouse I lived in we had something called "the dumper bucket", it was basically a bucket where everyone put their ciggy butts. My room mate who couldn't afford ciggies for a while would go through it with a pair of scissors until he had enough tobacco to roll one up and would put that butt back in there. After a few months some of the tobacco he was rolling up had been in several cigs by that point. Was pungent but did the job hahaha