I just remembered when I was 15/16 and I was hanging for cones and I couldn't go outside due the way the wind blows and where's its located and my oldies always had their bedroom windows open, so I decided to "experiement" this method, I used to pull endless of cones, and "blow" into the pillow.... and did that for few weeks and my oldies had no idea that I was smoking pot in the bedroom, but they "knew" I smoked pot, and one day my mother was changing the bed sheets / pillow covers and she was shocked to find a pillow covered with bong smoke/tar marks of my mouth all over the pillow from blowing into the pillow to buffer the smell... and I was busted....and my oldies got pretty mad, not for me smoking pot, but for having weed and bong under "their roof"...... it was a funny sight to look at that pillow......my mum threw that pillow away and brought a new one and she checks the pillows all the time when I visit them.
But nowdays I just go outside and have a joint while my oldies are few metres away and they always give me funny looks when I am smoking weed front of them, but I just don't care, they have to dealt with that.
When I moved out of shared house and moved into a flat on my own few years back, and the funny thing that my old neighour was sooo stoned, and said "hey man...." and he forgot that he had a bong in his hand when I was moving my stuff into the new place, and he was scared of me for few days that I will "report" on him until I invited him over for few beers and then ended up a all night bong session, and it was cool because when I am out of pot, he always has some and when he is out of pot he came over to mine for few cones, and this "neighour pot-sharing system" was pretty cool and handy, and lowers the "neighour paranoia".
Really if you are worrying too much about the smell and stuff and paranoid, maybe it's time to be nice to all your neighours and be friendly, it pays, trust me I know, my neighours are pain in the arse, but it saves me a hell a lot of hassles.