I have been doing some high internal work recently and use my slx with a cone screwed onto the quick release angle adapter with an unger  fixi  clamp,  with a scrim for detailing, after squeegeing using a wagtail. 
I found the wagtail best used as just a squeegee as using with the pad at high level is tricky. 
Just use your normal applicator on the cone to wet up the window.