Try flushing it out with some WD40 , then if you have a can of air , spray the heck out of the pivot and get all the Wd out you can manage , wipe off with paper towel and qtips or whatever you have , the point is to get as much of the dirty/gunky WD40 off as you can , then gently lube with some
3n1 or Breakfree , something along those lines.