<< Your comment regarding contemporary magnets being too powerful made
and it seems it may be rather difficult to acquire suitable
weaker ones. >>
the nature of the physical univese (macroscopicaly) is entropic making weak
magnets is no biggy heat a magnet or apply lots of physical force (hit it)
disrupts the alignment of the atoms and weakens the field the effects are
sometimes temporary so the longer you apply heat the longer it will be weak.
just make sure not to over do it