yep. Just alternate between the razor blade and the rag w/ acetone. I found mineral spirits work well too. With both mineral spirits and acetone, make sure you clean the sin out of it before you re-seal it, as the silicone won't stick very well (oh and for the fishes sake).
I did this very thing about 2-3 days ago and worked great. (unfortunately I cracked the glass as I tried to move it to where I could clean it.
I did this very thing about 2-3 days ago and worked great. (unfortunately I cracked the glass as I tried to move it to where I could clean it.