I'm liking the orange peel based removers.
here's several options I found in this article LINK
Don't know if it would work for your application, but I love the black scotch-brite paint stripper wheel that attaches to a drill. You can get them at Wal-Mart or any hardware store. They work wonders on cleaning stuff off aluminum if you're not concerned about stripping it back to the bare metal. I used one wheel to clean all the corrosion off all the windows on my camper. They were 35 years old and came out looking like brand new...... Then used the same wheel to strip a REALLY sloppy silicone job off the roof seams....
of Judi and Jed
you might try wd-40. it has worked for me before...also try a heat gun. hope this might help you out
You might also try MEK - Methel Ethel Keytone A very strong solvent, wear a respirator and gloves. Nasty stuff but eats most anything, including paint. Hope this helps, Tony, Joy and Cool Paw Luke
I have been told mineral spirits does the trick also might get a silicone caulking removal tool like they sell to remove bathroom caulking it is a V shaped tool you slide along to get the caulk out.
i just did my windows also,i used kerosene an let it sit a minute and all the old came off with rubbing with rag with kerosene on it...