With those ingredients it was both effective and you could use it on babies and animals without hesitation.
Certainly safer than the bismuth subsalicylate they use now.
I used the old stuff and it did work.
I also used yellow mercuric oxide and mercurochrome until all mercury products were recalled and banned. No one I know ever had any bad effects and the physicians I have spoken with tell me the mercury compounds were ineffective and yet, they all prescribed them as long as they were available. When I asked them why, no one had an answer. They worked for me and my extended family for as long as I can recall.
Still not sure I would ingest bentonite for diarrhea, especially since the *green clay* is also expensive. OTOH, pectin is not only widely available, it can be homemade from apple peels.
http://www.wildflowers-and-weeds.com/The_Forager/pectin.htm