Back in the 1930's seems there was an Aggie County Ag Agent (grass & weed expert) making a presentation to rural cotton farmers on how to eradicate Johnson Grass.

On conclusion of the presentation an old farmer in the back raised his hand and said,
"I'll tell you how rid yourself of Johnson Grass. Just get a bunch of moonshine whiskey and pour it all over that grass. Why in no time, these East Texas Baptist will have it gone right down to the root."