I find spraying the filters with plain water from a hose sprayer works for me. Seems more logical to simply dislodge the gunk than soak and I've never had a buildup that needs detergent/acid to remove. I do it twice a year even though pressure never goes up but a couple of pounds and it takes about an hour to disassemble, thoroughly clean and reassemble. Pressure washers are supposed to be too powerful and could damage the filter material.