I know I might be necro-ing a dead thread but it's a problem that has been bugging me for a while and I just decided to fix it lol.
As an alternative to submerging it in warm water, I pulled off the pump after taking the straw out of the bottle and cleaned the section around the pump. First with a toothpick but realized that was a bit too thick. A paperclip works well in stiffness and being thin enough. They're crystallized deposits so they're pretty hard to see but all in all it should take about 5 minutes and restore you to the correct dosage amount in no time.