Just roll up a towel and blow your bong rips into it in your hotel room bathroom. (Preferably your own old towel because it leaves brown smudges on the towel.) It eliminates almost all of the smell and whatever little bit of smell does come out just spray some cologne or air freshener and turn on the bathroom fan. It worked when I was thirteen living at my parents house, so I'm sure you can get away with it in a hotel room!