I am having gtrouble with my euph, Boosey and Hawkes Sovereign 4 valve. I use Blue juice to lubricate the valves and practice two hours a day but after 5 days the valves are sticking again until more blue juice is applied. Is it best to wipe all the residue off the valves PRIOR to appying new blue juice or should I just apply new blue juice straight onto the valves. The guide pins (metal attached to valves not plastic inserts) are clean and the guide grooves are also clean. What else can be done? :-?