These vibrators are no more dangerous than normal records - frequency of vibration is approximately 400 Hz and amplitude is about the same as + 18 dB track on HFN test record - and furthermore, the "surface" is not relatively hard vinyl, but carbon fibre bristles. In more than 20 years, not a single cantilever damage.
The only risk is perhaps with stone cantilevers ( sapphire, ruby, diamond ) - and only if the cartridge in question can not track amplitudes above 70 micrometers. The most notorious of these were old Dynavector Karat series, the models that pushed the cantilever lenght to above - or better said below - minimum lenght that still allowed for
tracking of high enough amplitudes and reasonable life expectancy. Original Karat series used 2.5 mm long cantilevers, Karat Nova 13D used ( as the name implies )
long cantlever made of diamond (these were reportedly VERY prone to breaking the cantilever - normal music playback as well as vibrator cleaning ).
The optimum lenght was eventually found - in 1.7 mm diamond cantilever, as used in DV 17D cartridge, currently in its (MK)3 incarnation. These are "bussines as usual", no abnormally high cantilever failure rate reported - over decade at least.
The only thing one must be careful with vibrating cleaners is to lower the stylus on the surface with carbon fibre bristles and not the surrounding bristle mounting ring. And, of course, you have to perform this on stationary platter - if your turntable is a stubborn automatic machine and refuses to lower the arm if platter does not turn, you will have to at least unplug it from the mains - if not finding ways around its automatic action that will allow lowering the arm to the stationary platter. Please see my Sleeping Beauty posts for one of the most stubborn tables in this regard.
Edited by analogsurviver - 12/17/13 at 11:22pm