You can take anything out of context, and fit what ever meaning you want.
The basic of chemistry never change, especially when you get into the basic foundation of life. Some things are toxic in large level, but in the right quantities is how life is created.
There is risk in anything you do in this hobby, especially when you have to deal with equipment malfunction.
Ammonium chloride is used as a flux in preparing metals to be tin coated, galvanized or soldered. It works as a flux by cleaning the surface of workpieces by reacting with the metal oxides at the surface to form a volatile metal chloride. For this purpose, it is sold in blocks at hardware stores for use in cleaning the tip of a soldering iron and can also be included in solder as flux.
Would you put Ammonium Chloride, in your tank?
If you start a new tank, with no life, and put 1 drop of Ammonium Chloride per gallon.
200 gallon system would need 200 drops of Ammonium Chloride.
In 6-8 weeks you will have life.
Do you want to drink this stuff?
Saying stuff like this to make point is not a proper gauge to put what in a tank.
Debates like this is fun, well losing two dosing containers did suck, lol.