This might be a dumb question:
I've been reversal processing black and white negatives for a while. The bleach I use is a Potassium Permanganate / Sodium bisulfate bleach. WOuld the magnet recover the silver from that bleach or is the silver from this bleach unrecoverable? I've been taking it to a local chemical dropoff site, but I'd be interested in using your magnet if possible.