This is the most over-the-top design I have ever made!
A see-saw, with a powerful electric actuator, two slaveboys and some big rubber cocks.
Their ankles are chained up so they can't get off, and their dicks are in chastity so they can't cum.
Rashid immediately punished the slave who failed to sell. Right there in the market hall, in front of everybody, the buyers, bystanders and most importantly, other slaves. He wanted this lesson to be a motivation for other slaves to give their everything when examined by a buyer.