I have used both Satin and Gloss sprays with discs that were prone to remain "sticky" untreated. They do work in protecting the ink layer from water/humidity/sweat. They also prevent a printed disc from sticking in the player when "eject" is pressed.
Care must be taken in spraying the Gloss to ensure a dust free environment or the specks of dust will show up on the finished surface.
Apply 2-3 very light coats at 20-30 min intervals.
ArgyllCMS profiles: Black Point Compensation gives composite black when checked