Rocky always has had an obsession with my moles or pimples or freckles or anyone's thinking about it. He loooooves to preen them, however, as you might imagine, its very painful. I've always discouraged it. When he does it, I say, 'No' and distract him or remove him from my shoulder/chest/neck/wherever he is that hes accessing them. This had seemed to be working, but the past few days hes been rebelling and will go after them as soon as he comes out of the cage. It takes alot of work to distract him from them... One time I flinched when he did it unexpectedly and my head bumped into him, sending him in a flying panic. Poor baby.

My question is... Does anyone have any experience with this type of obsession and what did they do to solve it?

My mothers Quaker parrot likes to pick at her moles. He also likes to nibble off the cuticles on her nails! Ouch!
She has worked and worked with him to get him to stop. The big thing that worked was not to yell or raise her voice. If she did he would do it more. Also he was banned from her shoulder if he nipped her moles. He soon learned that shoulders were a privilage and not a snack bar.
If he was really determined he would get a time out in the cage and she would ignore him for a while. HOpe this helps. It does hurt! I have had him pull out my eyebrow hairs before and nip my earlobes. Not cool.

Princess, my green cheek cinure, is the same, she ned to preen any imperfection. Then of course the spots she picked at on me are a little rough so she has to keep preening them and, well you get the idea. She also loves to rip off cuticles, bite through my nails and seems to think my lips are impefections that need to be bit off

I took your advice Val and when he kept persisting, I made shoulders off limits for the rest of the out of cage time. Hopefully eventually he'll get the idea he's not allowed... However I'm pretty sure he knows already, he just does it anyway lol!

Levi used to be a neck biter and boy did it HURT! If he didn't stop after a couple times of me telling him NO BITE firmly, I put him in his cage for a time out. Of course telling him he was a bad boy, mommy said no bite. He doesn't bite my neck any more! It didn't take him too long to figure out why he was being put in time out. Probably 5-6 times. He hates time outs, and usually takes it out on a toy in his cage by beating it up and acccking at it AND me! LOL
I usually do time outs for about 10 mins or so. Or at least until he settles down and starts playing nicely instead of being a brat.

Yes Justin my gcc's love to preen us and out come any little hais they can see, tiny little hairs! Yep moles, pimples etc. We had to break Bella of it she was so good at it.
We stopped letting her sit anywhere except our hands. Ever time she would sneak in a pluck we told her no. They hear the tone of voice you use, the inflection. If she continued we put her back in the cage and told her why. She has stopped!

Things are going well with this! I do what you did tealcandtina, which is only allow him on my arm or hands if he's going to persist, and if he won't stop persisting, put him in his cage. He HAATES that lol. Its working; now, he preens gently. He only goes after my beard(lmao) or simply licks my face (lmao again). Hes realize pimples and moles are off limits. If he strays and goes for a pimple or mole... down to the arm.