Unger do a first rate razor type, fold out blade.
Its 4 inches long and when opened out and folded back on itself, can then be clipped into the handle that would normally hold the squeegee channel.
It is the ideal piece of kit for this job.
You can use the stanley scraper, but the stanley blade is shorter, for a lot of scraping you are better off with the unger knife.
You can get bigger ones again, but they really aren't as good.
Stanley also do a small razor type scraper too, fantastic for the ceramic hob, and real nifty to have in your pocket for the odd bit of 'nibbing off'.
Using the scrapers that are designed with this function in mind is really the only way of cleaning up glass covered in paint/silicone/putty and so on.
.............unless its frosted glass or tulip glass (uneven, patterned surface stuff), if it is then you're stuffed
Ian