Landlady Chris Azerkane, who runs the pub with husband Rafai, hopes that the loo lid would get a good bidding from Royal fanatics. Chris revealed that Camilla used the seat after she unexpectedly turned at her door and asked to use the toilet in her bar - Hare and Hounds in Framfield, East Sussex.
After using the loo, the Duchess returned to the bar and asked if Chris had any sloe gin.
"Unfortunately I didn't - so she had a Stone's ginger wine instead. She wasn't with Charles but she looked beautiful in a really smart coat," said Chris.
And now, Chris is auctioning the toilet seat to raise money for the Royal Brompton and Kings College Hospitals, in London, where her 16-month-old grandson Omar is being treated.