Sjogren's Syndrome Support Group
Sjogren's syndrome is an autoimmune disorder in which immune cells attack and destroy the exocrine glands that produce tears and saliva. It also associated with rheumatic disorders such as rheumatoid arthritis, and it is rheumatoid factor positive in 90 percent of cases.
Slippery Elm Bark is also recommendd and comes in sprays which is supposed to turn into a gel when mixed with water and leave a film in your mouth which may alleviate some of that dryness you're having.
There is caution noted when using Goldenseal. It's only recommended to use up to 3 weeks and then stopping. I didn't see any caution surrounding Slippery Elm Bark but may have missed that.