I recently got a call from a member who just bought a 3/8 air powered roof cleaning pump. He had the big nozzles they sell for the Delavan Fat Boy, and he was not getting any spray, and was trying to do a roof.
Thank God he had the 5/8 hose we suggest (garden hose nozzles fit it), and we sent him to Ace Hardware to buy a plastic garden hose nozzle, to finish the job.
One, when I was cleaning a roof, my only ball valve/nozzle assemble broke, so here is what I actually did. I took a box cutter, cut my hose, and using rubber dish wash gloves, finished the job by putting my thumb over the hose