No doubt someone will be along in a second to tell us that car brake cleaner has oil in it. Hopefully just for once they'll have an example of one this is actually true for
Allegedly some car brake cleaner has oil in it. :P
The only time I've seen evidence of this was after I sprayed most of a can over an old rust bucket of a bike to get the encrusted crap off the mechs etc.
After it evaporated there was a massive oily patch just in front of the front door, although I suspect it was just the solvated crap left behind after the cleaner evaporated.
note: do any spraying away from the hawk like eye of the other half.