If the breakdown max voltage is 200v and you charge it up to 199 you it will remain charged at 199, if you get over 200 v you will get all the energy will discharge destroying the dielectric... dangerous indeed..
water always keep around 1v of charge because most contaminants conduction bands start around 1,24V or more...
my capacitance meter as is automatic reads only resistance even if is very pure distilled water...
if i charge the water, it seems like will never discharge, the meter says cap is charged... even if i keep shorting the electrodes...
might be that thing about the microcapacitors stan talked about