I thought it was trichloroethane, too. I double checked. It is chlorothene.
It smells of turpentine but there is an sickly-sweet undertone to it which is not like trichloroethane. I use trichloroethane to clean the film residue from cinema projector gates. I am familiar with what it smells like.
I do have a darkroom. I was thinking about trying them and I probably will.
It's just best to check things out before you go fooling around with unknowns.
Apparently, the Kov-A-Mar is some kind of lacquer. I've been doing a little research and that's what I found.
P.S. To "smell," in this case means to carefully waft the scent from the bottle, not stick your nose into the open bottle and snort. I learned my lesson early in life when somebody handed me a bottle of reagent grade ammonia and I said, "Hey, what's in here?... Snort!" I'll never do that again!