I'm sorry to hear that you are unhappy with your Renuvo. The pad itself is fairly absorbent, but it will need to be saturated as you start your project in order to provide a full, even coverage. This can be done by holding the trigger and moving the pad side to side on the surface to completely coat the pad. The trigger is intended to be used as needed and even at the lowest flow, the unit is not intended to be operated with the trigger pulled constantly. The pad should retain enough material that a brief trigger pull is all that should be necessary to reload it, regardless of the flow setting. The unit does not require a glass-smooth surface, but the surface should be properly prepped for staining, including having all protruding nails hammered back in. Depending on where the tank was leaking, there may be a couple things that could cause it. If it is not seated completely into the unit, the valve may be opened but the opening not completely sealed. This would cause the tank to empty, but removing the tank from the unit would stop the leak. If the lid for the tank were to be too loose or too tight, that could cause leaking as well, and removing the tank to set it on its side and then removing the lid, reseating the lid seal, and screwing it back on should resolve the issue.