I bought a ball that looks identical to yours at a garage sale today for a dollar. I was able to get mine cleaned, heres how:
I put a 1/2 inch of acetone in the bottom of a pint canning jar.
I set my gazing ball in the center of a large rag (an old towel).
Use a paint brush to paint the ball with the acetone, swirl it around with the brush and then wipe it all off with the rag.
Don't let the acetone dry or you'll find you've only moved the dull stuff to a different place.
Keep repeating until the ball is almost clean. I was down to about 1/8 inch of acetone in my pint jar. I then mixed 2 drops of dawn and 1/2 inch of water and using a sponge I washed the ball with that mixture. Then go to all soap and water.
Mine is now nice and clean and shiny.
For those with sensitive skin be warned that acetone is tough on skin, use gloves. Home Depot sells acetone and gloves.
