my process , 1000 gal tank , 60 gal rinse - all done in field
As soon as pressure drops - run in ~ 20 gal , spray out,
run in another 20gal , spray out,
empty rinse tank,  spray out,
stop in field, open tank valve, drain out on the ground. 

Refill with next chem.
Spray enough (edge of field or in road) to charge booms with new batch
Spray.
In ~25 years of custom app, about 30,000A per year, I had 1 chem burn on about 40' going from SB burndown with residual - to wheat post.