In the past I made a series of weedless hard frogs using small disc magnets.
I painted them with Createx water based paints, and top coated them with Solarez UV resin.
I found I had to top coat them to keep them from rusting.
I got the magnets here:
https://www.apexmagnets.com/?utm_source=remarkety&utm_medium=email&utm_campaign=October_Promo_1_2022&utm_content=&_rmId=2nv693l2wgfYoe225DPVInron1r1P3cBxGKENDKG