It’s certainly recommended. The S-Duo seems cool and comes with a gauge, too. If I had nothing, I might be going with this now, ultrasonic cleaning with just water seems like made for styluses.
In the past I used a vibrating brush cleaner (similar to the Flux-Hifi Sonic), which is ok-ish too (but my guess would be not as good as ultrasonic). Currently I use a DS Audio ST-50 gel pad (despite people’s paranoia about residue):
What’s nice about the gel pad is that it’s a large area and I am less scared of breaking my expensive MC cart. It seems to clean very well (at least as far as I can see with my magnifying glass), at least when records are clean and there’s not much dirt on the stylus.