It wouldn't work for flash.
Set the camera to f8, about 100-200 shutter speed, flash to about 1/2 power (close work requires less output)
shoot a few things in different 'poses'
check pix for depth of field and exposure.
If DoF is too low AND exposure too bright, reduce f to 11 or 16
if DoF is too low AND exposure is OK, reduce f to 11 or 16 AND increase flash setting to +1 or +2 (or 3/4 of dial)
if DoF is too low AND exposure is dark, reduce f to 11 or 16 AND increase flash setting to +3 or +4 (or 4/4 of dial)
if dof is Ok (doubtful at f8), just adjust the flash to suit the exposure of the picture, less for too bright, etc.
Repeat test.
If flash is at max and exposure is dark, reduce flash distance to scene.
If flash is at min and exposure is bright, increase flash distance to scene.
This should take about 30 mins, maybe, and if actually more fun than it sounds.
When you're happy, make a note of the flash setting, camera setting and flash positions and distances - this way you can just repeat it from the notes with minor adjustments for the scene.