SUMMERTOWN, Tenn. (AP) — A horror house that promises an extreme experience that can last up to 10 hours requires participants be medically cleared by a doctor and sign a 40-page waiver.

The McKamey Manor experiences in Summertown, Tennessee, and Huntsville, Alabama, also require visitors be at least 18, insured, and pass a background check and drug test.

WFLA-TV reports that owner Russ McKamey offers $20,000 to anyone who completes the tour, but he says no one ever has. He records each tour on video — for his own legal protection he says — and then posts them online, showing participants quitting in humiliation.

It's costs nearly nothing to enter: just a bag of dog food. The website warns of physically demanding environments, but McKamey says the manor is a mental game.

Watch the video McKamey shows all participants before they enter:

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