As far as chain-cleaning machines go, be prepared for some messy business. The KaBoom Chain Degreaser machine does the trick for us because it's the easiest to use of all the machines we've tried with less mess, and got the chain clean in the process. This popular cleaning machine has been around a while.
It’s our favourite for a number of reasons: filling it with liquid is done after it’s attached; a large capacity reservoir holds plenty of fluid, allowing the heavier grime and grit particles to settle and not get picked back up and spread onto your chain, and keeping fluid loss to a minimum; it’s also easier to keep level than the rest because the latching arm reaches around the back of the derailleur jockey wheels, making it easier to hold on to.
The only downside is that lid closure is less secure, and not as positive as metal latches used by a competitor. You still end up having to put some rags or paper down to catch the spillage, because there’s no way to escape the fact that this is basically a messy job. But it means you can put away the large coffee can filled with white spirit…