You should try the Neodium magnets out of a hard drive, you certainly wouldn't want those to clamp round your finger.
Talking about magnets, if you have a grandchildren who want magnetic fake tongue piercings, don't let them & warn their parents.
There's a magnet underneath the tongue & a fake stud magnet on the top of the tongue but they can easily get swallowed & it can up as a bowel operation to remove them.