I used this:Silicone Remover quite successfully the other day on my van.
A strip of sealant had been run across the top of the windows that was too much to scrape off. Just use a gun to squeeze over the top and leave for a couple of hours or so when pretty much just wipe off.
Amazing family weekend with old steam engines, classic car displays, market stalls, and full catering and bar. And camping on site - Save £25 by booking in advance.