Good grief that sounds like my dog!!! I swear she has to be the pukiest dog I have ever seen!!! Tho she usually does it in her crate while I am at work and has only gotten her head in it once.
I know that when I say this I am going to get all Sorts of people YELLING at me but this is what I do.
If I hear her stomach rolling I pop her a couple of tums or rolaids, and it does seem to help. She DOES NOT get these on a regular basis for those of you who think I am nuts, just occasionally.
OR you can try your local pet food store and try the charcoal biscuits to help settle her stomach. I tried those too and they did pretty good.
good luck!!