I seem to have got quite a few residential jobs recently with the big type above the window vents, as these are 1st cleans I go over the whole window and frame first, then go round again cleaning just the glass so the problem of them dripping/spotting is virtually eliminated, 2nd cleans onwards obviously only do the complete window once so do you tend to give the vents a good scrub and hope they dont cause problems or try to avoid them completely, I'd rather clean them totally myself but read somewhere to leave em well alone, how do the experienced here get around it, clean or leave?