Listerine (aside from the alcohol free) is high in alcohol.

I also heard hydrogen peroxide is another way to let a snake let go.

Wouldn't hot water be more dangerous for a snake? (Risk of burn?) I'm not sure how much alcohol/Listerine/hydrogen peroxide a snake would need for it to be considered dangerous (or why, exactly?), but it seems like hot water could possibly cause more long term damage?

I know snakes are an entirely different kind of animal, but I've given my dog hydrogen peroxide in an emergency to induce vomiting when he ingested some pieces of plastic off of a diving ring. The main drawback I could see with hydrogen peroxide is that after it's opened, if it's not used within a certain period of time, it oxidizes and turns into water. (Making it entirely useless if you need to go use it if it's been sitting there for a while).