It is not an "emergency" feature at all. It is there in case the door opener fails so you can open it up like people did before there were garage door openers.

Short of busting a window in your garage door or making a hole in it, I don't see how you can get the coat hanger to the release latch.

Most garages, especially detached ones have side doors that can be opened a whole lot easier than going to that kind of trouble. A lot do not even have deadbolt locks on them. A screw driver will pop them open in about 2 seconds.