As in many other aspects of life, it appears that the why of the matter may have taken a backseat to the what of the matter.

It is Russell's method to remove individual, personal, alone aspects of his slave's existence, and from that view, I see it as a wise choice. That is said with the assumption that Russell takes care as to the medical/hygiene aspects of the matter. Given what else I have seen of him, I see that as a safe assumption.

Not something I would personally consider at the outset of a relationship. However, I am not Russell nor is he me, and, relationships change and morph as more of each player's personality comes into the clear light of day.

I would suggest that his motivations and reasoning deserve first and primary consideration, before the mechanics of the method are dissected.