I have to disagree here. I don't know about the cheap electrical units, but the lightbulb method works extremely well. I have a 'smoke bubble' thing which is essentially a prefab lightbulb vape. The secret is a little practice and much patience. This might sound weird, but I've found that each bowl gets two distinct periods of vaporizing. When I first tried this, I would stop after the first and end up with fairly potent leftovers (tested by smoking). Be patient. Don't burn, but keep vaping til it's truly spent... or buy a Volcano.