Ive bought it a few times. I just USPS ground it home to myself. There should be a donation bin at the airport and exit points.

Seems rather wasteful for tourists to buy a can of bear spray, carry it around for a week, then throw it away. But sad that coming up with some kind of system to hand it off to the next tourist is hard? Otherwise everyone would use the rentals and there wouldn’t be so many in the trash.