Followed the directions and cleaned the trap with success. I don't have mine with the utility drawer underneath so I used a shallow pan to (slowly) catch the rinse water still in the system (once I dislodged the assembly and tilted it forward). There will be a few gallons, so be prepared to cycle through emptying the pan into a nearby bucket. Also be prepared for the crap you will find in the trap (ugh).
Thanks
Peter