You intend to have a gentle chat with them when they come back, just to explain that it was a bit rude to take without asking Well that's our plans ruined. Thanks a lot! You will take something of theirs that's important without asking and hide it You stub your toe. What do you do?
Zap a wet one in the microwave for 2 minutes every day and replace it every 2 weeks. Better yet, use cloths, towels, and rags that you can toss in the washer or clean with bleach.