I've found a small lifehack involving shampoo using a magnet (strong magnet, not neodymium) to solve my "tipping the shampoo off the shampoo holder" and "nudging the shampoo holder off the wall" problems. Not that pretty but it does the trick. I tried to use a hook instead of magnets, but it was miserable at its job.
Magnet coating is prone to rust, so I've put it in a plastic zipper bag, rolled it up and bound it with adhesive. Rust will cause the magnet to brittle and possibly crackle and I don't want this to happen (I don't care if the binder clip rusts).
Despite those efforts I've started to notice traces of rust on the magnet. Water has effectively managed to enter the zipper bag; I blame capillary action.
I was wondering is there is a simple way to protect the magnet. I thought about epoxy glue or hot glue, but I have neither of those and also I'm not sure they are water resistant.