No luck @woodcock - running in Verbose mode for the past 24 hours
index=<indexname>| fieldsummary didn't show the field whereas
index=<indexname> XXXPassword | fieldsummary shows it.
And as we said,
XXXPassword is a rare field...
The first command is utter nonsense but the 2nd command should already do exactly what you are asking. To make the first command "work" you should do this (but I wouldn't):
index=<> | rename _* AS INVISIBLE_* | table *