I prefer to be less wasteful and more environmentally friendly, filling them with junk data , erasing the drives, and finally checking the disc's for remaining data (there isn't any) before selling them.
Note, I'm talking about my own personal drives, if somebody wants to spend thousands trying to get data off one of my old drives then so be it, at the end of the day I'm just a normal guy with a normal job,, so a very unlikely target to be investing money into recovering an old drives data.