Bazz,
I've been W/C for 20yrs in April and will be 1 Yr WFP.
The fact is ; Some don't like it wet!!! And................
It'll drive you up the wall too!!!
Walking away leaving wet thruogh windows

And you will get a few call backs because you did it wrong

But be honest with your customers. Don't tell them too much at first.
As for losses........I found that in the end I have lost all those "Victor Meldrews!!"
Pain in the arses who never realy respected what I did...........Pleased to see the back of em!!
Now ALL my customers can see the benefits of WFP. All get their frames done, doors washed, windows over conservatorys and slate roofs, roof lights and a few have Garage doors washed !
Stick it out...........you'll gain more than you loose
David