I bought a Pallo brush to clean out grounds from around the shower screen after each pull but it seems the bristles are awfully hard. Will it damage gaskets by pushing it up there and running it around the screen?

I found all of those extra stiff bristle brushes to be less than optimal. What I use is a 1/2" china bristle chip brush that you find in the very low cost brush bin at the big box store. Cut the bristles down to about 1/2" long and trim the wood handle to 1 1/2" long. This will get all the coffee grounds out of the locking groove and off the portafilter seal o-ring. You will be verifying the effectiveness of this tool when you dissemble the group for the periodic clean and lube.

Yes, thanks, that makes a lot more sense. I've been reading up on the group disassemble and will tackle that shortly.

Thanks for the tip about the China bristle brush. Good call, easy and useful.