Chains get cleaned in a media blast unit using ground corncob. I can then see what the wear/dull/ rocked/ect. factor is for sharpening purposes. Parts washer system could be used also but then you need to let the chains drip dry awhile. Just my way of doing it. Chains are dry and do not collect grit from grinding this way. If you have just a few , Gunk engine cleaner works in a container big enough that you can use a brush in with high enough sides so you are not splashing the cleaner all over. ( kerosene works ok as well, just doesn't always get all the pitch off at times) Naphtha might work ok as well never tried it. I have used fuel oil as well in a pinch.