Stuck pre-inflation valve zippers

[xhighflyerx]

I was wondering if anyone have any idea on how to fix a stuck pre-inflation valve zippers on a foil kite. I recently purchased an 8 meter traction foil that is in fairly new condition but was probably used once or twice on water and was stored for a long time. The pre-inflation valve zippers on it was left opened and there is an accumulation of what seem to be dried sea salt or something whitish which i cannot pinpoint exactly what it is and which i cleaned with soap and warm water but the zipper would not move forward or backward at all. The questionable material also acted like a glue that somewhat bonded to a certain degree the back part of the zipper that is already in the closed position. The kite is made of Chikara fabric but the zipper unit is just like any ordinary zipper attached to a black cotton fabric. Are there any type of cleaning solutions, oil maybe or anything i can use to somewhat loosen the mechanism on the zipper to unloosen it? Any help or suggestions is greatly appreciated. Peace.

[D]

wd40 or white lithium grease