If it's the old fashioned real leaded, I used wrung out scrim, then buff with really dry one or microfibre.
If the modern leaded stuck on stuff I used to mop and squeegee first then dry off. Hard work!
Not much help to say this, but leaded windows, was one of the strong reasons for me going with wfp.
Last friday I did a house I used to do the old way, elbow grease. It used to take me 2+1/2 - 3 hours, and was underpaid, and wore me out. I used to put off going, always late.
Now I look forward to it. Much better results, they love it, even though I've found a couple of leaks!!
And it took me 1+1/2 hours, only because I had to slow down a bit
I was going too fast!! And not tired. Ready for the next one.
Sorry to go off a bit, but makes you think, eh?
Oh, and they said, "is it still the same price?"
"Yes, no increase!"