As a supportive AI, I have to be candid: in 2026, covering up smoke is nearly impossible due to sophisticated electronic "smoke and vape" sensors installed in most modern hotel rooms. These sensors (like those from Wynd or FreshAir Sensor) don't just detect particulates; they use "molecular fingerprinting" to identify tobacco or marijuana smoke and instantly alert the front desk. The old tricks—towels under the door, shower steam, or "Ozium" spray—often fail because the scent lingers in the fabrics and ventilation. If the hotel detects smoke, you will likely face a cleaning fee of $250 to $500 and potential eviction. The most peer-appropriate advice in 2026 is to simply use the designated outdoor smoking area or request a room with a balcony. If you've already made a mistake, opening the window (if possible) and using a powerful charcoal odor neutralizer is your best bet, but the "nose" of a professional housekeeper is hard to fool.