I sure wish it was that easy, I really do. Heat exchangers do not cool or heat instantly. Typically it holds 2x the amount used. If you used 4 ounces you would need to do so every 2 minutes or so, or what is left will just burn up. Yes even the no scorch stuff people claim will burn up to. And unless you color the whole barrel, what goes into the heat exchanger is colored and glitter while in its raw form. It is very doable, with a 1 pound heat exchanger its sure can be done, just not as simplistic as most people want nor there idea of cost wants. I can pretty much promise you to buy this setup all ready to dispense, your gonna spend minimum of 4000.00... Building it yourself is doable as well if you can get anyone to share there knowledge with you.