ive got to admit i have done all this sticking pads onto my brush and found that they come off after a couple of weeks and they didnt do that good a job anyway , also when the pad comes off it leaves the glue on the brush and if you forget and try to use the top of the brush to remove bird muck ,instant scratch.
what i have recently done is purchased one of gaz brushes the tuff brush which is made for upvc cleaning and conservatory roofs .
i have left the brush on and used it for normal window cleaning and really an impressed with the results it removes bird muck without a problem
so i now use the brush always , its a bit heavier than the normal brush but im not bothered as it can save me plenty of time with bird muck
gary