How to protect wood hamster hideout

[Teal9]

Hi Everyone,
I have a wooden hamster hideout that I would like to protect from my hamsters pee.
I see a lot of recommendations for plastikote but the clear enamel is not available.
I live in the United States, does anyone have any alternatives?
I am looking at
Bioshield, Herbal Oil - Non-Toxic, Primer and Sealer for Food Grade Surfaces
Food grade, non toxic safe for kids toys. Its linseed oil with essential oils. They cannot tell me the essential oil mixture because its a proprietary blend.
I'm also considering not sealing the wood and just leaving it.
Thank you all for your help in advance. Its very much appreciated.
Teal