Why we use potassium permanganate and tannic acid in gastric lavage?

Here are some... This Q has been around without being answered. Here is my take based on what I have studied and retained about life & medicine. I'm sure that, through decades-long experience, the mentioned mixture has been proven to provide optimal ability not only to neutralize the unwanted mis-swallowed toxic materials but also protect more for stomach and intestinal mucosa as well as being more palatable.