Shower Massage Blues

I have a plastic Brass Craft 4-position hand-held shower head, with one position (my favorite) being the pulsating massage. Recently, it had stopped pulsating, though the water pressure seemed fine. I wanted to take it apart to see if there was something obvious wrong with it, so I tried to unscrew the center and then I tried to pry it off with no success. Finally, I just cleaned out the little holes with a small nail and it began pulsating again. My new problem is that it now leaks like a sieve when it's in the off position, which it didn't do before I messed with it.

Are these hand-held shower massagers designed to be opened up, or are they permanently sealed?

They are all different. Not sure on yours. Next time try soaking it in vinegar.