Barbera,
I DONOT consider it a good idea to leave strikes or anything valueable in your room, at anytime.
I donot know where you will be staying. But some of the casinos has rooms with safes in them. Use the safe, even for a small charge. Or some of the casinos has safty deposit boxes, usually no charge.
The idea about leaving valueables in the room after the maid cleaned, is questionable. As if the maid let herself in to clean. Why can't someone go back and let themself(s) in again.