Check out Citrus King. It is concentrated citrus oil. Works well. I softens the adhesive so that you can wipe it away. I found that a razor blade scraper did a good job with removal once the citrus softened it.
I think it is about $70 per gallon. A gallon will do the whole camper.
This product was recommended to me by customer service at Keystone.
I think it works better than most of the other stuff. I tried them all.
Enjoy
,
lcarter