I would get him to a vet to be checked out. I noticed bubbles in one of my snakes mouth a couple of weeks ago and ten days later had taken three snakes to the vet to get meds for RI. They are separated from the rest and appear to be doing much better now. I would do what your vet said, but mine did tell me to increase my temps for the snakes affected and provide them with a ten minute soak everyday to keep them hydrated and help break up the mucous. This has actually been working and the snakes seem like they can't drink enough water while they are in there. If your vet doesn't reccomend this you might ask him/her about it. Giving them shots of baytril every day as well. I just wanted to share my story with you, but I would get him to a vet asap. Hope the lil guy does well for you.