"He who marches out of step hears another drum." ~ Ken Kesey
We use three different ones. The Zep ones from Home Depot, when they stop working I squeeze the bottle and stuff will still come out of the nozzle. Bug or weed killer pressurized hand pump ones. When the wand stops working I cut it off and with some adaptor fittings put a normal garden nozzle on the end of the hose. The third is a steel one I picked up from Mc Master Carr. It has a screw on lid, open it up and add the solution close it up and add air pressure to it then use as a regular sprayer but they run upwards of $90.
yeah non kidding. i put press cleaner and haze remover in them. no problems.
i buy cheap ones at the dollar store they hold up and work great. and they only cost a buck.