Questions about paste & PVA glue

I'm a junk journaler who has been experimenting with rice paste at different consistencies.

(Junk journaling often involves upcycling old books by stitching new signatures into the cover, so it's not full-on bookbinding from scratch).

I like it (it's cheap and less messy/easier to clean up than PVA), but am a bit concerned about vermin. I read a comment here saying that mice like to lick starch paste. I read another comment saying that if you mix PVA with starch paste, the mixture is non-water-soluble after it dries. Would this prevent the mice from enjoying it, then?

If so, I am wondering what ratio of PVA to paste to use. I understand that comes down to personal preference, but my main concern is that if I give one of my journals to someone as a gift, they might end up with some new "friends" that they didn't expect (as well as a damaged journal).