The 2015 BBUK contestant previously auditioned for X Factor before he appeared on Big Brother without success.
Now Simon's back for another go, and was seen auditioning for the judges earlier this year.
Hoping for success on X Factor after his Big Brother appearance, so-called Showbiz Simon performed Robbie Williams' Let Me Entertain You - with a few lyrical changes.
"Tell me, do you do panto?" asked Sharon Osbourne after the wacky audition.
Simon got enough yeses to make bootcamp but didn't make it through to the Six Chair Challenge.
Now he's hit out at the ITV series, complaining to the Daily Star newspaper: "I was waiting for 12 hours to audition and I didn't eat anything or drink anything and you're in a hot room all day.
"I felt like I was being treated like an animal."
He also took aim at The X Factor judges Simon Cowell, Louis Walsh, Nicole Scherzinger and Sharon Osbourne, saying: "They get what they want and then you're forgotten about."
A spokesperson for The X Factor said in response to Simon's claims: "We work hard to ensure all contestants needs are met and kept as comfortable as possible during all stages of filming.
"Contestants are welcome to take breaks and leave the holding room in between filming as well as being provided with water and being made aware as to where food is available."
The X Factor is back this Saturday and Sunday night on ITV with the Six Chair Challenge featuring the Overs, Boys and Groups categories.