I've been down this path. If you're only using the Ultrasonic on its own, then I would say not at all.
However, if you're using the Ultrasonic unit with a surfactant, then I would say, yes absolutely. I saw the light after reading the Audiophile Man's post on it. I tried it and it delivered a big difference in cleaning, whether new or old.
So, I've done it both ways. Using a surfactant is the way to go. And the more you do it, the better it gets. (I'm talking 2-4x; I'm not that obsessive :-). You just keep removing stuff and that helps get the stylus ever more deeper into the groove.
Hope this helps.
