oh boy I HATE pinched harmonics, these are my one weakness, I just dont have the natural ability to play them consistently, I've practiced them solidly for days on end and gotten no better!
I also have a friend who could do it right away, and can happily pick squeal every sodding note on the fretboard!
I find them easier to play on the high strings, and on the naturally harmonic places on the fretboard 3,4,5,7,12 fret areas, but otherwise I'm stuck (no need to offer me any advice, I simply cant do it! lol, although your condolences would be appreciated!)