How to tune 1/6 MT by ear?

Hello all!

Yes, I know how to tune Kirnberger, Werckmeister and of course 1/4 K
meantone by ear on my harpsichord. Now does anyone have a recipe how
to tune
1/6 K meantone (besides just stretching 1/4 K...). Or is counting
beats the only
possibility?

Michael Meixner