Forget the expen$ive chain cleaning machines-they are all worthless.
Get a chain with a powerlink, a bottle of citrus degreaser, and an empty plastic bottle (1 litre milk bottles are best, but 2 litre coke bottles are good, too.) Remove the chain, put it in the bottle, add a small amount of cleaner, and shake. Add a little hot water, and shake again. Drain, and fill with hot water. Shake. Repeat . Pull out chain, and dry it in the sun for about 2 hours. Install and lube.
Those chain cleaners only clean the outside of the chain. The dirt that causes the damage is inside the links, and the only way to get that out is with the method I just gave you.