Iām not prepared to completely agree with Uncle Larry without more facts, but I will share this:
Some years back John Downey visited with the Steamin Demon, a portable that used high water volume under low pressure that some of you might have used.
We went to a local EMS base that I used for truck mount demos and overall kept clean as a contribution to the community for about 5 years.
Each time I did it, I (over) applied the original
Prochem Ultrapac āstinkyā Trafficlean and ārinsedā with Prochem
All Fiber Rinse. No one else ever cleaned the place.
The Steamin Demon had a window, and I was shocked at the white detergent I saw being removed, and how many passes it took to get it to rinse clear.
I learned a lot that day.
So can you leave enough residue with a prespray for encap to work?
Perhaps...