I have the Park tool cleaner, and I'm totally underwhelmed. I think it's because unless you clean your cassette thoroughly as well, your clean just gets dirty (at least blackened) nearly immediately even after running it through the Park tool cleaning machine.

It's so easy to just degrease it without a machine just with a stiff brush and a hose to rinse off the degreased gunk - that way you also can deal with the cassette and derailleur, so the whole system comes out sparkling at the end - and lasts. That Park tool chain cleaner was one of my worst purchases, honestly - while it cleaned the chain, there was really no point in having a super clean chain unless your cassette is super clean, and it takes less effort to do it without the chain machine.

As carpediem said, I agree that the hose (gently pressurized stream of water) makes the huge difference. A bit of forced water to get all the degreased stuff off the chain and cassette works so much better for me than that reservoir of no pressure degreaser that you can't even compare.

I'm sure some folks here will say that with only the brush and degreaser, you're not getting deep into the chain for cleaning, and that may be true, but I haven't noticed any loss of function or shorter lifespan of my chain. An ultegra chain lasts well over 2500 miles (haven't exactly measure, could be a lot more than 2500) for me and when I change it, it's usually a preemptive change when it stretches to just over the 0.75 mark, not a necessary one since something's not working right.