Question On Getting Splattered Crud Off Exterior Window

[driz]

I have some Malta Low E French doors that got some splattered stuff on them over the years. Thinking about it the only thing done out there which could have splattered droplets this big would be cheap deck sealer or the neighboring white paper birch tree. I tried everything on the stuff from vinegar, to windex to turpentine and finally the hottest stuff I have, laquer paint thinner. Even the thinner wouldn't touch this stuff which is really strange. I can just catch the edge of the little globs with a fingernail. Whats the next thing, buffing with rubbing compound or the humble razor blade? The main thing I don't want to do is scratch the window up as I was amazed when my wifes cursed dog once managed to scratch the glass with his toe nails.

[HayZee518]

use a single edged razor blade in one of them holders and scrape off the goop

[driz]

What about scratching? I tried some green pot scrubber 3m pad on an out of sight portion of a similar window and it left some scratches. Hell I always thought you needed something real hard to scratch glass. Could that be some sort of coating to watch out for?