With 14,50€ only, the Vapo-Bowl is most likely the cheapest option to turn your bong or water tool into a vaporizer. The Vapo-Bowl works pretty much with the same technique than the wooden VaporStar or the more expensive, glass-only VapoCane.
The Vapo-Bowl Vaporizer consists of a regular bong bowl (available with 14 and 18mm fittings), as well as a metal cap with a small valve, which is simply placed on top of the head.
You can use the Vapo-Bowl with either a regular lighter or with a torch-lighter for even more dense and cloudy vapor. Therefore you will need to aim with your torch flame at the metal cap vertically, but you should avoid pointing the flame at the valve directly, by slowly moving the flame closely around it, best. Once you have learned the technique, you will be able produce dense and cloudy vapor very quick without combusting any of your material, this way.
If you want to use a regular lighter, you will need to hold the flame above the valve, horizontally and suck in the flame through the valve. However, it should never get in touch with your herbs directly, if it does, simply increase the distance between the flame and the valve.
This method is easy to learn and doesn’t vary too much from what bong smokers are used to, anyway. Although, you might inhale butane leavings this way, as well. That’s why I personally prefer the more indirect method, described above.
Anyway, with 14,50€ only, you can’t go wrong with the Vapo-Bowl. Perfect for bong smokers who want to stop combusting, but don’t want to change their habits a lot.