take an empty bottle of spirits, higher the alcohol content the better. swirl the dregs of whats left in the bottle so it coats the whole area, i assume this also helps diffuse the 'fumes' in the bottle. then hold a lighters flame to the opening, but be careful as the flame shoots out the front and you will get burnt fingers. also if using a dark bottle dont put your hand over it when you think its extinguished, sometimes it isnt and it will give you a perfectly round blister on your palm but its a cool party trick and you can do it a few times which the left overs in a bottle
