This was my first unresponsive yoyo and served me well, but I could never get past the awful awful barbed wire and skulls etched into it:
I chucked the halves into my electric drill and went at them with varying grits of sandpaper until the metal was nice and smooth, and the etchings gone:
It was that way for a week or two, but then decided that some color would be nice. I re-chucked it in the drill, and using a brush and some pearl blue paint I mixed up carefully painted the inside of the cups. After that, clearcoat was applied (again, spinning in the drill). Although it doesnt get as much use as my Magic T8 and of course YYF Horizon, I can at least stand to look at it ;D, and it’s no big deal if it gets dinged up.