Possible mouth yeast infection in a rooster

My friend emailed me. She thinks her Banty Rooster has a yeast infection in his mouth.

Does anyone have any natural treatment suggestions?

Does anyone have any good links for more information?

I knew such a thing was possible but had blissfully blanked it out of my mind.
Here are a few links :http://www.poultrydvm.com/condition/candidiasis
                                    https://www.backyardchickens.com/threads/yeast-infection.552949/
                                    https://www.chickensandmore.com/chicken-diseases/

Basically wash/rinse the area with a solution of Apple Cider Vinegar and water, then treat with an antifungal if you can find one that's what you consider safe for where it is on the chicken.
I hope she caught it early. Some of those pictures I looked at were seriously troubling.
Best of all thoughts!

My friend was here today, and told me that she found your reply extremely helpful Kristine, and wished me to convey her thanks to you. She used Apple Cider Vinegar on him and thinks he's looking better already. It made her feel more confident to have some of her thoughts supported by the links you sent, and also the kind thoughts!

That's wonderful!
I'm so glad I could help. The first link - to the DVM one - is really helpful to me.  I'm glad she feels better about her care for her chicken.
Thank you for telling me!

We used to use Gentian Violet for thrush in kids. It worked well and has to be less toxic than some of the newer treatments. This is Blue Kote and I use it topically on my animals. You could spray it on a cotton bud and apply to oral surface several times a day. Not a vet here but I am a MD/PhD pediatrician.