I cut the subwoofer housing part off of the magnet using a sawzall and then used a grinder to smooth the metal off.

I then inserted an eye hook with big fender washers on both ends and red thread lock on the end.

I plan on attaching a rope to it and use it to retrieve things off the bottom, or hold tools, etc on the work bench.

Just a thought to recycle what you may just be discarding as something useful.