"goof off" brand sells a caulking remover that dissolves silicone as well. It says its good for use on glass. I have used their products and they work great. Home Depot sells some of the line, but I'm not sure about this particular product.

Always looking for Red Indian Tins, McColl Frontenac, McColl Bros., Buffalo (prarie cities oil co), Stellarene and other western canadian tins.