From the Benchcrafted website:
Attaching Crubber
You can use any glue you'd like to attach Crubber to your vise. We've used liquid hide glue, yellow carpenter's glue and contact cement. Contact cement is nice in that it likes to peel or rub off cleanly when it's time to replace the Crubber. The other glues will have to be scraped or planed off, or removed with hot water, although they do provide a little more holding power than the cement. Bottom line, they all work fine. Make sure you use plenty of glue, especially at the edges
That being said i attached mine with yellow glue and have had no issues with it.