Before administering any trials with your dog, check with your vet and vet healthcare team. Never ever try on any human medicines or home medications with your dog.
The most vital thing is to keep your pup hydrated at all times.
However, for an upset stomach, you can give a small amount of boiled rice mixed with plain (no salt or spices) chicken broth. Watch out for any improvements or antagonistic effects. Another simple way is to make him fast for eight hours.