The problem with stuff like that is that if you point out the errors of scholarship in a sensationalist sendup of George Washington, people will insist you are defending slavers and slavery.
George Washington’s slaves were freed upon his death, his dentist is recorded to have purchased human teeth from Washington’s slaves (and a set of his surviving dentures includes both human and hippo ivory), sacking was commonly recycled in colonial America by slaves and freemen alike, and while the belly wool of sheep is indeed often fouled with manure at time of shearing and of an inferior grade compared to top wool, it is necessarily cleaned during the process of making cloth. So given what I see of Coard’s so-called “scholarship” I would not expect to learn anything meaningful from his work.
It was a quickly-googled link to illustrate a broader point [1], not an academic citation. The bits you object to originally came from Wiencek rather than Coard.
IIRC, Washington’s will didn’t free his slaves upon his death; it instructed that they be freed upon Martha’s death. They ended up being freed a bit earlier than that, probably because Martha was uncomfortable living with people who were eagerly anticipating her demise.
Martha also owned slaves of her own. These slaves were not freed, but were instead willed to her relatives.
“Purchased” teeth runs into the same problem as Jefferson and Sally Hemings: enslaved people cannot meaningfully give consent. Nothing is voluntary when one party in the transaction holds the power of life and death.
Personally, I don’t see a huge ethical difference between slaveholders who pass on slaves to their heirs vs those who don’t. It’s a monstrous evil either way.
[1] “the founding fathers were fucking goblins and it’s always good to be reminded just how fucked up they were”