As long as u make a BIG job of first clean
I agree that the 1st clean is going to shape how the job works out in future. I roll my eyes when i read about people saying there is no point going back and checking the windows. because it's 'a waste of time.'
I've detailed a house after using wfp for 8 cleans until they dried spot free. (I mentioned this house on another thread that i charged £40 and they wanted a discount cos i take 25 minutes.)
I would say 40% of 1st cleans i do have spots and runs after being checked later on, so i'm under no illusion that wfp makes everything perfect. But it can be, once the windows have been made clean the 1st time.
Spend the time doing the job properly the 1st time, no matter what, or how long it takes and you will reap the rewards for as long as the job lasts.
That 25 minute job for £40 used to take me 2 hours trad and almost 1 1/2 hours wfp + detailing for those first 8 months. Now i fly and i know they are good.
Using wfp on a 1st clean and hoping for the best is tantamount to playing russian roulette with our business. I don't see the point in risking a newly gained job for the sake of returning later that day to check and maybe tidy up.