Re: has anyone ever tried or heard of this?
The glycerin causes the big fluffy clouds. So the more glycerin, the more smoke I think.
But if you add 'neutral' glycerin to some flavoured shisha the flavour will fade, and you'll only smoke shisha for the clouds, not for the taste.
But a juice... I don't think that will be nice.. if you want big clouds, rather add some glycerin to a shisha bowl for some extra clouds.