What i do, its not as if i really have to hide it, but i still do it for good measure when im smokin in places besides my room...
I just crank up the shower a little early, *MAKE SURE you put a towel under the door* when it starts to steam up a lil bit i turn on the exhaust fan and smoke, as the steam gets thicker the smoke gets thicker, anyway, after this, just wash like normal and if it stinks when you get out either spray a little febreeze or just keep the shower steaming and pour some shampoo on the floor of the shower... makes the room smell like it.