Ditto on never using dishwater soap and do use TSP.
I buy the stronger liquid TSP, mix it w the correct amt of water per directions for 2 gallons, then add 1 cup of bleach. I add to a 2 gal pump up sprayer and spray the filters applying about 1 gal per filter, so it takes 2 total applications.
By the time I've sprayed the last gallon on the last filter, I rinse out the pump-up sprayer and get a bottled water and let the filters soak a little more - all of this should be done in the shade [no direct sun]. Then crank up the hose to full blast w a solid narrow stream nozzle and hose down the first filter I sprayed going from the bottom upward. This keeps the solution in the pleats and prevents streaking. When I've worked my way all the way to the top, I give it one top to bottom washing. Repeat on cartridges 2, 3 & 4...
Now, since you probably have just your skimmer baskets in the skimmers like we all did, you're fighting a losing battle bc what gets past the skimmer baskets make it to the pump basket then makes it to the cartridge filters...BUT, by installing white poly-spun hair nets, your life will be changed from ever having the same degree of intensity of cartridge filter cleaning...
Here's a link to make your life 1000 x's easier for $5-7 bucks per yr..every one I've given these to have all purchased and installed them...now you can join TFP forum for this great tip...Merry Christmas..tstex
https://www.amazon.com/Disposable-Hair-Spun-Bonded-Polypropylene-White/dp/B072XXLC13
Note: EZ OFF will eat the rubber and other material holding your pleats together...only use this type of cleaning agent on approved surfaces...don't inhale it either...