Concur. Slaves were too valuable to treat as bait. Yes, certain slave owners were cruel and inhuman, but that was the exception. Since slaves were extremely valuable they were treated with much more care than an indentured servant (European). Indentured servants were kept for a period of years, so each day meant they were worth less. Slave children were just the opposite; every day a slave child got older, it was worth more.
Concur. Slaves were too valuable to treat as bait.
I wouldn't be so sure. Looking for that movie poster posted above I saw several illustrations and postcards that perpetuated the story. They may have just been tasteless drek for gullible tourists but there they are:
That last illustration from New York World in 1896 shows the barbaric practice used in Ceylon (now Sri Lanka), so it wasn't just an American atrocity.