I think you are referring to a deionizer. There is a thread on here "Anyone using a deionizer" (sorry, I am technologically challenged and don't know how to put the link to that thread up). You can search for it and there is a bunch of info on that.

 

I believe this is the link you seek https://www.ford-trucks.com/forums/1...re-washer.html
Read at your own peril, i.e. not responsible for your wallet getting lighter!

 

I use a CR Spotless deionizing system to rinse my vehicles after I was them. I am absolutely sold on it; so much so I changed from a large system to a small system I can carry in the RV for occasions I have to wash the rig and truck. I use baby shampoo and water to wash (with a lams wool mitt) to wash vehicles with. I also have a small, 1 GPM , electric pressure washer to rinse with so minimize the deionized water usage.