Another idea is to leave old clothes or thrift shop clothes you brought for travel in the room. It's possible that the cleaning staff may be able to use some of the items. Not the underwear though! On a beach trip, a friend of mine with small children brought along inexpensive pails, shovels and other beach toys for her kids. When leaving for home, she left the toys in the room in hopes that someone who worked there could use the toys for their kids.