SABERTOOTH HYGIENE: SURVIVAL OF THE CLEANEST
All cats devote a large chunk of their time to fastidiously taking care of their hygiene and if anything, sabertooths had even more reason to do so.
Right after killing a large prey, as it should do at least once a week, a sabertooth of the genus Megantereon would look like a bloody mess -literally. Unlike modern cats, its killing bite relied mostly on causing massive blood loss to ensure a rapid death of its victim, and that implied a somewhat untidy spectacle. But if we could find the sabertooth at any random moment, chances are we would find a pretty clean animal, which is only what you would expect from a cat.
If we could time-travel and come across the sabertooth Megantereon, it is very likely that it would be grooming itself!
A sabertooth smeared in old blood would be pestered by flies, it would be prone to skin conditions, and would be more easily smelled by potential prey, so it needed to be quite conscientious about its grooming.
But of course there are other benefits to grooming, incluiding the fact, obvious to any cat owner, that it feels good and decreases stress! Social species would benefit from mutual grooming but a solitary animal, as Megantereon most likely was, would need to twist a bit around. But then its long and flexible neck would be a welcome aid in reaching those difficult spots!