Re: has anyone ever tried or heard of this?
You could just take a cheap brand and destroy it with glycerin, it'd give you the effect I *think* you're looking for.
You'd have even less flavor than flavorless-brand-X has to begin with, but you'd have huge clouds.
While you were at it, you might as well put TONS of ice in the base too to help. If you're not concerned with flavor, go all out. Milk+Ice, etc.
All the old tricks.