You may also wanna try getting a towel, and some big pliers.

wrap the towel around the perch (the gold part), get the pliers in the slots on the perch and use that to spin it.

Another thing I do if I don't have pliers available is leave the allen wrench in the tightening screw, and use it to turn the perch. Sort of like a simple machine..

definatley spay it w/PB blaster or WD as others said.. but be sure to wash it off as it will attract more dust.