Well, it's both. As you state, they are required to add stuff to ethanol, to make it undrinkable. On the other hand, if something is already poisonous, they are

Well, it's both. As you state, they are required to add stuff to ethanol, to make it undrinkable. On the other hand, if something is already poisonous, they are required to add the same stuff. In the case of cleaning alcohol, the manufacturer would 'add' (or 'not remove', depending on the process) the methanol even if they weren't required to. As such, the cleaning alcohol is poisonous and they have to add the other stuff. My point was merely that that situation is actually more common than the first, because methanol is cheaper than ethanol.