This is the de facto standard for chain degreasers. I've used others and they've worked fine as well, but for some reason, I always go back to buying this brand. It gets the job done for sure. I run the chain through the PT chain cleaning tool twice, cleaning the tool out in between runs, and the chain ends up so sparkly clean you could eat off of it.
This cleaner makes it so easy to get your chain clean when used with the Park Tool CM-5.3 Cyclone Chain Scrubber or another chain scrubber tool. I use it about every 3 weeks/600 miles. Fast, simple and effective. It's amazing what a good chain cleaning and lube will do.
I use this cleaner to completely de-grease chains when using lubes that require total removal of existing lubes. The Park solution cuts through everything on your chain with minimal scrubbing, though I recommend a chain cleaner tool with resevoirs and brushes to control the mess.
I use Park Chain cleaner in my chain cleaning device and it does a great job. I also use it to clean my pedals . I use an old toothbrush to clean the nonchain areas of my bike as well. Works great .