With the cost of modern fly lines and the small cost of the dressings recommended and sold by those who manufacture fly lines I see no reason to take chances with stuff found in the garage or under kitchen counter. Besides, that I'm told ArmorAll is water soluable which seems counter to where fly lines are usually used.
The stuff I use like Glide, Agent X and the Scientific Anglers dressing lasts a long time in use and besides, a little goes a long, long way.
In fact, I'll do you one better and use NO dressing on the modern lines that have the slickness built in all the way to the core. A swipe with a micro-abrasive pad brings a brand new finish to the top that is a dry finish which does not attract dirt.