Should be okay - reference the RAW and BARF proponents (a club I do NOT belong to.

) but for future reference, peroxide is a great vomit inducer. We pretty much give out a costco bottle of the stuff with every Clumber pup we sell. Clumbers feel that if something fits in their mouth, it must be edible. And if it doesn't fit in their mouth, then it needs some chewing until it does. You should talk to your vet about how much, but we just dump as much into their throats as we can, since after the first time this is done to any dog they are not terribly cooperative the next go'round. We figure that we only get about a third down their gullets once they have gone through this once.
Sadly, I have perfected a restraint method so I can peroxide our dogs by myself - and trust me they ALL know what the brown bottle means. We also have several of the large syringes that you can get from your vet or the feed stores, fill it with peroxide out of a cup, and then put that as far back in their throat as we can. Most dogs will vomit within 3 minutes, and we have found they tend to barf about 3 times for each time you dumped some in their throat. Clumbers, being particularly attached to anything they consider food, tend to take longer - as much as 20 minutes, but they
will give it back.
After almost 20 years in the breed, here is an incomplete list of things we have personally had to utilize the peroxide party method to retrieve :
1 lb bag of snickers mini-candies - all candies still in their wrappers, a "koosh" ball, feminine products, socks, gloves, an entire tube of eye antibiotic ointment, a children's glove (we have no idea when she got that - we don't have kids - we were barfing her for eating something else entirely!), cell phone battery, unknown specifically but she had gone through the kitchen garbage, eyeglasses, catnip mouse toy, something terribly gross and stinky out hunting once (we didn't wish to ID it once it came up - the smell was too horrid!), most of a bottle of 222s, and what ranks as most recent and most odd : chemical hand warmers. 2 separate times.
So peroxide is a good tool to keep handy and available in your household doggie first aid box. And if you have Clumbers (or most spaniels, honestly) in your hunting first aid kit too.