If the insides haven't been cleaned for a long time, then you have to give the whole thing a good wash. I have found that Unger liquid is pretty good, seems to cut through the tar without too many problems.
Again, if they are really sticky with the gunge I will take the sleeve off the applicator and wash the glass and the frames. With Unger liquid/GG3 etc you get very few suds, so mopping up around the frames with your scrim (or microfibre) is straight forward.
On pub windows I'll use a cut down squeegee (I have half a dozen or so of varying sizes)
Grit your teeth, accept the first clean is going to be a mare.
Subsequent cleans should come up well, but you have to wash and wet all of the glass including the edges of the frame where it meets the glass, if you don't, then the tar will quickly build up and the edges of the panes will start to look smeary.
When using the specialist detergents such as GG3 or unger liquid, repeat cleans are straight forward I have found, personally I always use a squeegee on pub windows regardless of the size of the panes. If it is a non smoking pub that is different, on georgian I'll mist with sprayer and buff clean, not the smoky ones though
Ian
