I always thought that the checking, cleaning and stowing of Quick-Don masks was a maintenance function. I would question whether continual removal from and re-stowing of them was beneficial, or even wise.
On one type I have worked on, MD-80, the boxes actually have a tamper seal on them to indicate if they have been messed about with. And take it from me, they are a complete pain in the proverbial to repack.
My advice would be to ensure that in the event of any spillage, or suspected spillage, make an entry in the Tech Log and get them checked and cleaned by maintenance.