Well, I read the comment on Ortofon’s website. It seems their objection is that the turntable could move while the stylus is in the gel thereby damaging the cantilever. I avoid this potential disaster by placing the Zero Dust on the plinth under a pad of post-it-notes that has been adjusted to the correct height to allow the stylus to drop in via the cuing lever.
Soundsmith's website doesn't mention Zero Dust specifically, but recommends Blu-Tack and no wet cleaning. I couldn't find anything on the Micro Benz website,