Gravel at bottom of pot

[Grim Tuesday]

I have a nice, ceramic, perfectly sized pot that unfortunately only has one drainage hole. I was thinking of putting gravel at the bottom of it to effectively make a lot of drainage holes (that eventually all go to the main one at the bottom) but I encountered this puzzling article by the University of Nebraska Extension. I have a really hard time understanding what they mean by it. Does anyone here have experience (positive or negative) with gravel at the bottom of a pot? I'm thinking like 1/2 inch river rocks, not sand.

Here is the article:
The Hard Truth about Rocks at the Bottom of Planting Containers | Nebraska Extension