In general soap just makes water more watery. And lets it soak in and remove dirt. Too much soap just defeats the purpose and can (will) grease up the water. Most detergent manufacturers recommend you use too much soap in wash machines - they would wouldn't they - that why theres a grease build up in machines. As a general tip use half recommended dose in a machine.
Just before we got our new F&P washing machine we had a technician in to see if the old one was economically viable to fix, sadly no, fuck built in obsolesce. He mentioned to avoid grease build up you should just drop in dishwashing tablet once every six to eight weeks and let it go through a normal cycle. He recommend normal dishwashing tablets not the ones with the ball.
Mind you my dishwasher would like a dishwasher, bought her some Aesop Hand Creme instead.