I was cleaning a new customer today from the rround that i bought, the windows are normaly trad, its been £8 under priced, anyway she said the last guys before the trader used wfp and it aparently ruined her wooden sills (they were perfectly fine) so i said to her that there is no differance between wfp and the rain! (sigh) i ended up doin it trad in the end twas a pig of a job as well!!!