Ok,..I've used this force feeding idea for several jobs now,.and I must say it really solves the issue. I added a 3-way valve on the inlet side of the 12V pump,..one side for SH and the other side is tied into my water supply tank and when I'm ready to rinse the injector system out,...I simply turn the valve to the water side.
What's really nice is the flexibility the force feeding gives me. Where without force feeding the 8 GPM pump last season ,..I would just have it pulling wide open.
I have the 12V pump wired into the solenoid and both turn on and off at the same time with the remote.
But now,using the little 1 GPM 12V to force feed,.......even at 10 GPM I only really need to open the valve about 1/4" of the way,.and that is a plenty strong mix for house washing. When I open it full for concrete or something else bad,.it makes a REALLY strong mix for DS'ing. Very flexible,.and I'm really liking it.
An added huge benefit so far is NOT HAVING TO UNSTICK THAT STUPID LITTLE CHECK BALL, Ha,Ha The pump has enough PSI to dislodge it.
Jeff