Watched Cake Boss last week and he steamed fondant...I have a black sphere (covered in fondant). Had to smooth, smooth, smooth.....there's a little cornstarch residue on there that isn't brushing off....Would steaming solve my problem?

If you want to remove cornstarch, just give the whole cake a crisco bath. Just put crisco onto a paper towel and then rub it gently all over the cake. Then come back with another paper towel and remove all the excess. (Sugarshack's method).

My understanding was that steaming was for the "shiny patent leather" look. It might take it out, but you would definitely have to do the whole thing. Or you would have a super shiny spot and then the rest would look normal.

Of course that is what you have to do with the crisco as well.

I use steaming a lot to set colours and give a slight gloss on my gumpaste bits, so I can see how it would work on fondant too. But, it would be a bit harder to control the effect on a large item like a cake (IMO).

I like the Crisco idea for cakes!