Maybe Cascade Complete liquid
I think the liquid dishwasher detergents might be way too 'thick' for the dispenser.
I got this one on Ebay for a friend a few months back. He used it in the office to just wash coffee cups, but, changed positions, so he could no longer use it in his new enviornment.
I agree, the pressure is a bit poor and I think you really need to 'pre-wash' or else, nothing would come clean.