I offer 6 weekly because I found that I was being prevented from cleaning too much when I did monthly. It was no loss because I got to the point where it was too much of a struggle getting the work done in a month. I do a couple of the bigger jobs at a different frequency but these are jobs where I could justify a visit especially for that job (i.e. three or four hours work for each job). Funnily enough, now that I'm using WFP, these larger jobs don't take that long any more. A job that used to take me three and a quarter hours on a ladder took me four and a half hours on the first clean with WFP. On the second WFP visit, it took me two and a quarter.