http://www.youtube.com/watch?v=alfLE4vyanQ
Works. Even though this is for RC cars…
That looks a lot safer than the other methods.
Still, I don’t think I have any yoyos I want to do that with. That’s just my thoughts.
I did this with my raptor and it came out nice. Here’s a tip though: use a dremel or a drill! This will take forever without a drill. It took me 4 hours with one, but that was because I was so inefficient. Also, I’m not sure if it will happen, but when I was using steel wool on my HM to take the dings off, it got black. I believe this was a burn, and I had to sand off quite a bit to get it nice and shiny. To prevent it from happening again, I didn’t spin the drill at max speed. Just a heads up.
If you can, please post pics before and after. I want to see how it went!
Good luck 
Yes, the black mark was probably due to overheating the metal by spinning it too fast. best to go slow with these.
Try using Drano Max Gel that you can get from walmart it worked on my Yoyofactory Popstar and just get some steel woll to remove any leftovers
From the looks of it, any highly basic chemical will work. This makes sense because you use a strong acid to anodize it.