I've done that with a hair dryer; I have even put smaller parts in the oven to bake for a while at a 150 degrees or so to harden the enamel. Wife never appreciates that, but the finish comes out strong and shiny (if its gloss).
OK, I have done a LOT of rattle can painting and it turns out pretty good if the proper time is put into prep. But, I would like to take it to another level as an alternative to powder coating. Now I agree that all-in-all it probably works out to about the same cost wise, but I like the hands...