DANGER!   The heartstopping-ness of cap-discharge is determined by energy, not by coulombs.

See the pdf: [IEEE 2009: electrical hazard classification system][1]

In general, it's bad to let your capacitors get into the 10-joule range and above.  That's for discharges across your chest, of course.  Significant heart danger starts at 20joule discharges.  Below 10joules, the main problem is muscle contractions, getting sliced by slamming sharp objects etc.

0.001uF and 6KV gives 36 millijoules.  Pretty safe, if a bit painful.

Still, the cardiac effects depend on energy density, not just joules.  If you stabbed a sharp-terminal capacitor into your ribcage, the energy delivered to the pacemaking system would be orders of magnitude higher than if the same capacitor terminals were touched with two hands.

When working with cap-discharge systems, only use one hand.  That way the accidental discharges won't go across your chest.   Or better yet, always remain very fearful, and paranoid that you'll make a mistake and receive a bad zap.  Some serious respect (if not sheer terror) goes far in encouraging proper research beforehand, and to avoid developing any ignorant risky behaviors when dealing with kilovolt capacitors.


  [1]: https://www.osti.gov/scitech/servlets/purl/956350