That's an excellent question! Incredibly, no. As an antonym to pozzed, based is a rare term of post-'80s black slang that's actually worth uttering.
I'll take note. I actually first found out it was black in origin just a few days back, despite hearing it regulary since atleast 2019.
Hmm I don't think you'd be able to pick up any silver/gold coins is the only thing, but it'd def be fun to try some day!
I don't know how it works but, wouldn't detectors spot gold/silver coins? I guess magnets won't though