Newbie Needs Help/Ideas/Suggestions Setting up DI System with Current Pressure Washer

Hi all thanks for having me!
I am fairly new to window washing, I mostly do residential up to 2 sometimes 3 stories if I have access from the roof, as well as I do some commercial (mostly storefronts). I was raised around the water treatment biz, as I worked for Rainsoft, my dad worked for Culligan for years and then opened his own water treatment company so I have some knowledge of R/O, Conditioners/Softeners, etc…
About a week into doing windows and squeegeeing my butt off I thought to myself, “self, I bet if I could rinse these windows with deionized water I would not have to squeegee them. Not to mention with the right equipment I could possibly reach windows higher up than I can now”. My original idea was buying a small open air trailer and buying a huge holding tank and having it filled with softened DI water. I would then hook my pressure washer up to the tank and clean away. However I figured it would be more practical and convenient if I could have a more portable type setup. I figured it should be doable as my pressure washer only uses 4 gallons per minute and it obviously only takes a few seconds per windows so I shouldn’t go through much water. I have a Graco G-Force 3540 Belt-Drive Pressure Washer 3500psi 13HP Honda engine.
In doing research I found some setups that seem to be meant for exactly what I am wanting to do, however I do not need a complete setup nor do I need anything extravagant since I already have my pump w/ pressure washer so I just need a somewhat small or reasonable sized DI system (if they make such a thing). Honestly I don’t work long days, nor do I work every day so I don’t need anything too hardcore like someone who is at this full time would. My largest account is just pressure washing the pavement at 6 Checker’s Drive Thru places twice a month which I don’t need the DI water for obviously. However I really would like to have this setup when I do windows.
I hope you all got the gist of what I am trying to do and what I need, and I really hope you guys can throw me some suggestions. Just please keep in mind I am trying to put together a reasonably priced setup that will save me time and leave the customer happy with nice spot free windows. I don’t mind doing work, putting together parts or anything like that. I once made a mini water softener out of PVC and resin that was about 18" long. You could hook it up to your shower head to clean off or even your faucet to drink from (don’t tell Rainsoft I kinda borrowed some stuff from them to make it lol).

thank you all for your help!,

You don’t want to run DI through your pressure washer.

I can help you. You can actually use a very portable system, consist of a electric pump trolly of 5 gals. You can contact me privately at 865 233 6109

Keep it simple its not that hard. A tank maybe a pump.

Out of curiousity…why?

You should take John up on his offer… He will have an easy solution for you.

Unfortunately I don’t have thousands to spend right now and after looking at his site it looks as if that is how much I will need for a waterfed system. I already have a pressure washer which has a perfectly good very expensive pump on it, I don’t see why I would need to by another pump and a whole other setup just for doing windows. I mostly do 1 story homes and small businesses, I just am mainly looking for a way to get the windows clean and dry spot free without squeegeeing.