Is food grade hydrogen peroxide safe?

Question
I foster rabbits, and someone looking to adopt told me a story about their bunny they currently have, who they are looking to bond to one of my fosters. They told me about 1.5 years ago, their rabbit was sneezing quite a lot (15 times in a few minute time span) and she took him to the vet, and did antibiotics 3 different times per vet instruction, but nothing helped. Then, she decided she would give food grade hydrogen peroxide, and in 2 days, the rabbit was no longer sneezing, and hasn't for about a year and a half. Would you happen to know why this is? I personally think maybe it was a coincidence, but I have no idea and I would hate to push aside potentially useful information. I would also hate to offend the lady if the information she is giving me is completely accurate and I just push it under the rug, because she only told me the story so I could help any of my buns who are in a similar situation, which I thought was very sweet of her.

I have never really heard about food grade hydrogen peroxide, and the information I get on it from google is quite controversial. Is it safe to give rabbits? The caged pet coordinator of my rescue just let me know that sometimes hydrogen peroxide is used to clear up hairballs.  Have you ever heard of something like that? I wouldn't normally be worried, but the potential adopter mentioned she still gives her bunny 2-3 drops per week of the stuff in the water, and I wouldn't want my foster to drink something that isn't safe or if she didn't need it, especially because if the water tastes weird, my foster could stop drinking and get GI stasis from the lack of water. But maybe I'm just a  paranoid bun mom.

Thank you in advanced!

Answer
Dear Ontario,

I have never used "food grade" hydrogen peroxide, and would never administer it orally to a rabbit or any other animal.  H2O2 is a highly corrosive oxidizing agent, and while it will probably kill microbes on contact, it will do so indiscriminately.  You would kill the good flora with the bad.

The reaction of H2O2 oxidizing releases a lot of oxygen gas, and the last thing you need in a rabbit's stomach is gas!

Here's what snopes has to say on the matter:

http://www.snopes.com/medical/homecure/peroxide.asp

They are an excellent resource for debunking urban myths with solid fact-checking, and they've done their homework on this one.

In short:  I would not use this for your rabbit.

Happy holidays!

Dana