I used the hylands teething tablets with DS who had reflux.. not really sure if they helped or not, but we used them with no side effects in addition to tylenol/motrin when things were really bad.
with DD I have used them but not too often just yet but she is on a beta blocker and I just worry about any interactions with her blood pressure so I don’t use them unless things are really bad.. they seem to help her. You can also rub some benadryl on his gums it will numb them a bit and cut back on the histamines that are released which will help with the extra drool.. i tend to use dye free for that so it doesn’t make too much of a mess. HTH.