i too was worried about moving over, but just did it and have only lost one customer, who was a pain anyway, so wasnt bother, just said ok no problems, u will have to get a new wc, as she maon about the windows being wet, the others aint bothered, i just some times say about h and s and most people agree, besides ladders should eb footed and taht means employing someone to hold the ladders adn then doubling the prices which usually makes peopel come around to wfp,
also there frames come clean easier, a lot of house where i live have green type mould on them as they havent been cleaned in years and they come up pretty good with wfp, as most custy are convienced by that
just say to the custy that u will do it for 3 months and if they dont like it you will go back to trad for them, jsut say to them that this will give them enougth time to make up there own mind rather that being told by other people that wfp is crap