I try hard to only roll my old fair dice on felt (in the past) or plastic (since 3d printers). They work by having hard corners, those wear down making the dice less fair when rolled on surfaces harder than ABS

I guess if your dice were pre worn by polishing you can't make them worse, and fair polyhedric dice are pretty much no longer available

Online dice simulators are probably fairer still

You haven't seen how some of the folks I play with roll.

Maybe the real Cthulhu was the impossibly mind-breaking irrational thought experiments we subjected ourselves to along the way! :D