Perhaps a fast food drink cup with water, well even soda, blow the exhale into straw therefore into water. That would trap everything sense it is only vapor. If the noise is not a problem. You know, like so many children do for fun.
I did the down my t-shirt method, works well. I have also did the stealth thing, hold the drag for a few seconds and about 5% comes out. The longer you hold it the less comes out. I have done that for a count of 5 and you would have to be staring at my lips to see anything.