For old QIC tapes, the big ones, I simply got out a screwdriver and
unscrewed the back plate off (2-3 screws), then pulled the tape out into a
plastic bag. Did about a hundred old tapes, the back plates were thick
aluminums so I had 15$ of scrap too. Had to pry off the steel pins with a
pair of ViceGrips locking pliers.
Unfortunately, I had to toss the tape itself and the plastic pulleys and
bobbins in the garbage, I would have liked to have recycled them but not
possible.
The tapes themselves were old 35 mb to 120 mb tapes, quite useless today.
I would not burn them, or nail gun them, or pound them with a hammer. Just
take them apart. Quicker. I assume noone is going to reassemble them.
If you really want to destroy them, commercial firms do that if you must
ensure that the data is destroyed. They will shred them and give a
cerifiticate of destruction.