I used Pine-Sol and some dawn dish soap mixed together. About 3 1/2 gals of water and 12 ounces of pinesol and a big ol' squirt of the Dawn. This is all a guesstimate. The heat was set on high (as high as It can go 180 degrees). seems to work much better than just water and the dawn soap. This ultrasonic is small but just big enough to fit a Q-jet, I wish it had a bit more power. Also, I do not let the carb sit on the bottom of the tank, I suspend it with coat hangers in the basket, this also seems to help. My unit is a KENDALL I think it is 450 watts but a lot of that is for the heat. Think I paid about 400$ for it about 2 years ago. Bought it online. I think the purple cleaner would be another good option but have not tried it yet.