Once you hit the send button, it’s too late.
That's a fact. I was just considering cleaning the contents of one device. "Bleachbit" (or `bcwipe` or whatever floats your boat) can't justify being expensive. The point of it is to allow the drive to be repurposed, so at most, it can cost the replacement price of a drive. Smelting the drive is more certain to rid it of the data, and if smelting is cheaper than bleaching, it's a no-brainer.