It can be cleaned off with water easily when wet. Once it's dry, it will dissolve in water, but it takes time and really needs a good soak to do so, which is not what you want to do with the wood. That is also likely to weaken the neck glue bond at the same time.

But you can use a sharp knife to remove as much as you can, and then sand back the rest. Rub the wood with white spirit or meths and that will show you if there are any patches still needing some sanding to get rid of the glue, as they won't absorb the liquid and will look lighter.