Originally Posted by
Polaris OBark
Mineral spirits are fairly harmless, but there is really no need to use it. Just start with a new chain, wipe off the grease it is packed in, and then the melted wax will displace whatever residue remains. The great thing about wax in the liquid form is it becomes a (safe) non-polar organic solvent, and unless you are starting with a previously filthy chain, it is all that is needed. Disposal is trivial, since it is harmless (apart from whatever the chain residue is) and it is a solid block that you can just put into household waste.
Im not a chemist, but this is my experience exactly. Just dump the new chain in the hot wax and swish around. Pre cleaning is not needed at all. I tried both pre cleaning and no cleaning and could not detect any significant difference. If you care enough to re-wax later, no cleaning is needed either. Just dump it in the how wax and swish. Me, I'm too lazy and just drip wax.
I do however agree with the OP. Solvent management is no big deal, when you realise you can use the same solvent over and over after letting it sit for a while. I use a few old wine bottles for settling out the gunk and decant back to a cleaning jar when I need it.