I live in an apartment and hence I will not use oms, gasoline, da or any harsh chemicals.
I used Finish Line citrus degreaser and pure orange oil which is the main ingredient and seems to be almost edible.
Used chain,
-I put the chain in a container, added a bit of degreaser, after a couple of minutes I add water, shake. Once dirty repeat this with new hotwater/degreaser mix until water comes clear.
- Wipe the chain with a cloth, lay it flat on a container and put just enough degreaser to cover it. I don't add water, let it sit for 30 minutes or so.
- Now shake it with hot water and mild soap. Again repeat this until the water comes clean.
- Wipe and put it in a container and submerge the chain in %99 ipa. Let it sit for another 30 minutes, if the alcohol stays mostly clear then take the chain out. The chain dries very fast.
For new chains I used both Finish line and Pure Orange oil,
-Submerge the chain in degreaser (again single layer on a small enough container). After and hour Orange oil did a much better job at getting rid of the factory lube in terms of sound.
So for used chains it is very messy but both seem to work, for new chains orange oil seem to be better. Moreover pure Orange oil seems to be one of the safest cleaners out there. There is only a nice orange scent, it is almost edible.
The problem is orange oil is very expensive. I put the chain in the smallest container I can find, lay it single layer so that I can use the smallest amount of degreaser to submerge it (Sram's boxes are great, ziplock bag also should work but they sometimes leak) and let it sit overnight (or 4 hours at least ). It seems to work.
Probably an ultrasonic cleaner will make this process much easier and decrease the amount of degreaser to be used(or allows one to use milder degreasers).
On a side note I have tried regular simple green on a leftover piece and it corroded moreover it didn't really do anything in terms of degreasing. I wonder if Simple Green's other non-corrosive offerings (aircraft or HD) are better?