I think they purchase TSV's just like the rest of us. They will purchase if it's something that appeals to them. But, as a sales pitch, they probably say they're buying sometimes when they aren't. It's their job to motivate others to buy and move product.
They've mentioned getting samples, or items for trial in their homes. I'm sure they keep personally used items like makeup, shower gels etc., but, I bet they have to return higher end items.
I get the feeling that the Q keeps close tabs on product and that they're not that generous with the staff. All to be expected. It's a typical business.