If you buy any gallon jug of antifreeze at the parts store, the label says that this stuff is actually ethleyne glycol, which has been used as an engine coolant for many decades. Brake fluid is entirely different, and is essentially a hydraulic oil used to operate the braking system. They're two entirely different things, and cannot be used interchangeably. If I learned that one of my A body buddies put glycol into his master cylinder, I'd take his keys away from him and keep him from driving his car until he fully and entirely emptied his braking system and refilled it with BRAKE FLUID.
