Whe i was in high school i had my method to a perfection to a point where my dad would use the bathroom seconds after and not know a thing.

I would turn on the shower hot as can be and sit on the toilet with my bub and smoke for maybe 7 minutes, all the while exhaling through the doob tube. I would only crack the window wide enough to fit the tube through and exhale through.

another thing that makes a huge difference is capping the bowls between hits, because with my bub it can let off some smoke between when you hit and when you clear, or between lights.

after smoking i would simply take a normal shower. by the end the room has steamed enough that any suspicious smells are gone, and it simply smells like shampoo. I had this down to an art where no form of smoke that smelled like marijuana would be released at any time during the process. foolproof,