Is this offensive to you?

No. This is harsh and honest. Some people may think that including such things in literature is "offensive", but if it's the truth and demonstrates how monstrous you think the traders were, then it's the price you'll have to pay for art. Art is painful, you know? When Upton Sinclair wrote "The Jungle", he included all kinds of nasty details that many people found offensive. But the meatpacking industry changed. He exposed evils that others were too afraid to write about. Bravery and honesty isn't something to be ashamed of. You don't have to go into huge detail--sometimes saying it happened is enough. But even the Bible is more frank with "offensive" subjects. As long as you have the right point of view with good intentions, I think it's probably okay.