Most of my buttons are machine washable and dry-able.
Just turn the garment inside out
so that the buttons don't bang against the side of the drum of the washer or dryer.
Look at it
like it's your coffee cup going into the dishwasher...
they're made the same way.
The
larger buttons and embellishments like the stars need more care and
need to be washed gently by hand.
Enjoy
your buttons!