It would depend on what the bad smell is from!
If it is from something you dried in there that somehow transferred a smell onto the dryer's surface, then you might be able to use a mild spray cleaner. It might be best to use a homemade vinegar-based solution, as you do not want to inadvertently use anything flammable in your dryer in case it leaves residue!
I can't imagine what you could have dried that would leave a bad smell, however. Is it possible that a mouse or other small animal could have crawled into the mechanics of your drier and died? If that could be the source of the smell, then you'll either need to have a mechanic locate and remove the remains or you'll have to give up and buy a new dryer! 
