If it’s very dirty that is not a bad idea. You would have to weigh out the time ilose to resin cost.
Can you do more work with the time lose which defeats the savings in resin ?
I don’t know what these guys are talking about wiTh water spots if you use regular water first. Ok so therr are water spots. A little scrub them rinse with the pure water done the waiter spots are now gone. Lol.
It’s the finished product that you will be judged on.
Your reasoning for using regular water first would be , Becuse the Windows , An frames an everything else is really dirty.
So it makes sense to me this method , but it is a 2 step approach which requires more time. Is the time worth more than the resin is what I’m wondering ?