Tom:
Magnets are hard to pull apart but easy to slide apart os twisting
the lid breaks the pull and more twisting initiates repelling. Should
work.

If you could incorporate some iron bearing material in the rim of
a small lidded box and had a hinged magnetic finial, you would
rock it over and break the magnetic connection to the rim.

Magnets have all kinds of interesting possibilities. If you come
up with some - please share.

charlie b