During the space program, they used TCE like it was water. Anything that came in contact, or could possibly come in contact, with liquid oxygen had to be washed in it so there wasn’t the tinyist trace of grease or oil on it. The United States Government demanded it.
Educated guess: it was used anywhere in the military that LOX could be found.
When I worked at [a well known electrical manufacturer] back in the 1970s, TCE was approximately as easy to get your hands on as distilled water was. It was officially considered “non toxic,” although it wasn’t good to get on your skin. Sucked the fat out of it, or so I was told.
After toxicity and groundwater pollution concerns began to emerge, the big manufacturers started using liquid Freon for a degreaser. That, of course, came to a screeching halt over concerns it was damaging the ozone layer.
I’ve been exposed to these things too.
An old coworker told me he’d worked in an ammunition plant where they worked elbow deep in carbon tet. Big troughs where they cleaned the brass.