depends what type semi's standard small 3 bedder,i clean frames most that trad dont so can clean quicker, takes me 15 - 20 mins,bay window ones 25 mins i do a good job tho,most trad guys i see are quicker than me but it amazes me how they clean so quick then sometimes i pick there work up and then i see why they are fast- there would be marks on the window like spider poo,or buff marks from scrim,or edge of glass not detailed properly,
i proberly do to good a job at times,its about just doing enough so customers happy though as frames sometimes wont need wiping everytime just keep on top of them