Hi,
You may read _OM’s posts here:
(some of them are already in this thread but Uial has regrouped them to make the reading easier).
Yes.
Some forum members have reported uncomfortable experiences after using Plasma on its own and/or excessively (feeling nauseous, high, etc.).
Grounding audios help preventing such symptoms + make last the Plasma effect longer (as explained precisely by _OM).