i dont see the point of it myself...if i want to apply chemicals to a job i just plug my pole and brush into my backpack that has my chemical of choice in......
Yer sounds right.
Take tube out put backpack on plug in chemical tube.
Maybe 50-150mil to fill tube before it actually reaches the brush.
Then when finish scrubbing with chemical disconnect tube put water tube back in back pack.
Then you wait clean water comes out to brush yet again so you can scrub/ rinse the surface.
Could do that.
But could be a bit time consuming.
Would think it is easier to just turn water off.
Put chemical/soapy solution into the brush via separate small tube attached to 1litre pump sprayer.
Scrub.
Then turn clean water on instant clean water no waiting.
Rinse Done.