Waterproof Coating For Grandma Goblin Experiment - Did it Work?

I did some experiments to see if I could make a waterproof coating for my Halloween goblins' faces. I came up with something that is waterproof, but it didn't cover the plaster cloth texture quite as well as I hoped.
I did find another solution that I might use, and there are several more experiments I'll be doing, after watching some videos on the ‪@VennasNature‬ channel.

We have a great hardware store in town, and a bakery, coffee shop, hospital, etc. - but no store that sells plaster of Paris. I'll do another coating experiment when the plaster I ordered arrives. (We also don't have a dog groomer, and my poodle really needs one. So do all the doodles in town. I wish a retired dog groomer would move to Hendricks, MN, and open up shop for a day a week. We could use a vet, too. I love everything else about this town, though... )

Links mentioned in the video - if I missed any, please let me know:

Venna's video about cement mache:    • DIY Hand Sculpted Chicken  
Making Grandma Goblin over a temporary form:    • Make A Fast Face Sculpting Form - Sculptin...  
Making Daddy Goblin:    • Sculpting A Happy Goblin in Clay  
Template for the mannequin I used for Daddy Goblin: https://www.ultimatepapermache.com/ma...
Dan Reeder's paper mache monsters and dragons book (affiliate link): https://amzn.to/3F2wOWi

Time stamps:
0:00 Today's waterproof coating experiment
1:02 How Grandma Goblin's portrait was made
1:26 Keep plaster cloth from sticking to oil-based clay
2:47 Portland cement and Titebond III wood glue mixture
5:01 Why I used wood glue with the plaster cloth
6:14 Trying the glue/cement mixture the first time
7:17 Trying the mixture the second time
8:20 Paper towel experiment for covering the plaster cloth
10:18 Ideas for more experiments
13:13 How I'll finish the Grandma Goblin head