A.A.
My son is 5 1/2 months old, and he's a huge drooler.
We have tons of small cloth bibs, and he wears those much of the time.
There is little you can do about the drool except keep bibs, towels, and extra changes of clothes nearby.
If his teeth or gums are bothering him, try some Hyland's Teething Tablets. They're a lot more effective than Ora-jel. They can be found at Whole Foods and People's Pharmacy.