bottom plug

The name Evan and Katelyn dubbed for the plug at the bottom of a candle mold which you then push the candle out of.

Katleyn: hey Evan, for this candle I think it'd look better if we used the bottom plug.
Evan: you know what, you're right.

Beer bottom butt plug

When someone consumes such a large quantity of alcohol that their bowls become uncontrollable so in turn they use the cork of their bottle to keep themselves from sharting.

After developing severe diarrhea from wine Steven used the cork of his bottle as a beer bottom butt plug.