A website about snakes in glue traps says to dissolve the glue with oil and then wipe down the snake with an oily rag.
Yup - that's what my vet told me.
Although I have no snakes now and don't plan on getting them again (I love the lizards), over ten years ago I had a large ball python that I adopted. When I moved into a new apartment with him, the management office didn't tell me that there was a glue trap underneath my stove. Well, the snake got out while I was at work one day, and - THANK GOD! - I discovered him quickly and got him to the vet. I had to give that poor snake several vegetable oil rubdowns as he was entirely plastered to the glue trap and coated with it. It was a gross process, but worked with time and elbow grease. I don't ever want to repeat that with any animal ever again.