me too, its not uncommon for a 1st clean to take about 3 or maybe even 4 times longer to get it upto scratch!
also i now do not do extensive paint or hard water removal as part of the standard service! i tell the customer after the first clean any axtra work i think the job needs and price accordingly, i use to stay on 1st clean for ever sometimes blading paint off and scrubbing frames and using chemicals to get rid of hard water stains (stage 1 corrosion)
no more, sod that! half the time they didnt apreiciate it! in fact most the time they didnt even know the extent of the damage to be removed (cleaned)
im constantly refining and inproving my service & business im very much the perfectionist type and being a "2 bob window cleaner" is never going to be who i am! if thats what a customer wants "flash and dash" then there talking to the wrong shiner!

also at the minute im trying to understand upvd and wood a little more to be able to offer a restoration service for those materials! any tips on this at all anyone?
G.B