On my Jandy 1400 cell, I did not want to submerse the whole cell, so I put a baggy over one end with a rubber band over the fitting to seal up the end. With the baggy side down, I stood the cell up in my garage sink and filled with the 4:1 muriatic solution. I filled it up until all the plates were covered with solution. My instructions said no more than a half an hour in the solution. My cell was completely plugged with calcium (I just bought the house so it wasn't my fault) so the mixture never quite stopped bubbling.
In my case the cell was so plugged with calcium, the MA bath did almost nothing. My cell was completely plugged and not generating chlorine, so I decided to get Medieval on it figuring I was replacing it any way. I literally had to chip the calcium from between the plates with a brazing rod. It was the only thing I could find that was thin enough to chip between the plates. I spent hours chipping, Ma bath, rinsing with garden hose. Made slow frustrating progress, so then I fire up the Power washer and hit it with that. Just blasted the cell from one end and then the other, and the calcium started fracturing and coming out. Between chipping with the brazing rod and the power washer I got the plates 90% unplugged.
Put the cell back in and it threw codes for a couple of hours and then cleared up and starting generating chlorine again. Bubbles out the pool return fitting like crazy when it is running. Been living on borrowed time for 3 weeks now LOL!
Good luck.
Charlie