The local authorities will not accept it. They also don't specify any rules for hobbyist darkrooms.

I lack room or an appropriate location for any of the on-site treatment options.

I do have friends that I have learned recently do use a steel wool treatment option, but they are a 45 minute drive away, so I only deliver it to them when my need for disposal coincides with a visit there.

If I had the room and the location to permit it, I would buy one of John's "Silver Magnets" in a heartbeat.