Errr..are we talking about cigarette smoke, or joint smoke?

Cigarette smoke will permeate the paint (eventually), and a great way of stopping it (or slowing it down) is to have a couple of candles burning in the room - they kinda cancel out alot of the shit that cigarette smoke makes (ie, the smell).

Dope smoke, like ~teknodppr~ says, isn't the same, and kinda disperses after a couple of hours...no worries

But hey, it's your Grandma's house, dude - ya gotta respect her wishes, init