Our chain block in the factory was decommissioned due to severally damaged chain. It's no longer safe for lifting anything with, but that doesn't mean I can use it for lifting. So I pulled apart the chain block and took the lifting chain and hooks (the chain used to turn the block is staying in the factory as it isn't damaged).
To get all the old grease off I washed the chain in a bucket with dish washing powder which seemed to work quite well, however I didn't take off any of the surface rust. I was going to soak it in a bucket of Coka Cola however I will wait as I currently have my eye on some more chain I might get and I'll wait until then. One quick note: Don't leave the chain in the bucket with any water, surface rust will form overnight.
So I got 7kg of chain for free, the goal is to have two, 10kg sets of chain for some compensatory acceleration.
The point of this post is to keep an eye out for things which might be useful and keep an open mind, you'll probably find a lot of good stuff. For an example of other throw away's I got from work see the straps on my lifting platform.