If you want esters (banana/clove) in your hefe, keep the temp up and let it blow off. If you want a cleaner tasting hefe, keep the temp down.
Controlling blow off IS NOT a reason to change the fermentation temp.
If you wanna waste some cash on that foam control crap, go for it, but it doesn't really buy you much in terms of brew quality.
Like others have said, RDWHAHB, and let it do its thing.
The smell isn't supposed to be all sweet banana and clove during fermentation. It's allowed to be a little gross and sulphur-ish. That's just what hefes do.