ive put windows+bottom sills, but i also do the top sills aswell, i dont make a special effort to do the frames, but they get some cleaning. i'll offer a 'full' upvc wash down of windows only once a year or whenever they look really bad,. i never did the frames when trad, only as an extra, always wiped the sills down. so i continue the same way wfp. nearly finished all of first cleans and had to redo a few along the way, but all in all im happy with system.