Can I use PVA glue with clay bole to gild the edges of books?

Hi bookbindit, my wife (non-Redditor) is trying her first attempt at gilding the edges of books and has got some red clay bole paste for water gilding. The instructions say she should use "animal hide glue" for example rabbit skin glue. Does she have to use this, and can she use PVA instead? Any other cheap vegan options we should consider?

Thanks in advance!