Can gunk clean your bike chain?

Yes, Gunk is good for cleaning chains. I just scrub it on with an old toothbrush, holding a shallow container underneath the part I'm scrubbing to catch drips. Keep on scrubbing the chain and then leave for 5 minutes. Then just hose off or wipe with copious amounts of water soaked in a rag until clean. It's a messy job and not as good as cleaning the chain off the bike but it works well as Gunk is a very effective degreaser.