Porcelain Throne - What does porcelain throne mean?

Porcelain Throne is slang for "Toilet." See an example of how people use it.
A porcelain throne is a fancy name for a toilet. It comes from the porcelain material used to make toilets and the royal seat a king or queen sits on.

Porcelain Throne

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Porcelain Throne

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Royal Toilet Throne

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