Those "Treepots" are manufactured by Stuewe and Sons:
I have successfully bought and used (short one) TP49 (4x9.5"),
to root more-than-average-long fig twigs before,
e.g. cuttings from UCD - less one decides to cut them in half
and later claim some 100+% [fautly math] rooting success rate!
I used them [pots] for some fat-twigs too.
Other Treepot dimensions are available (e.g. 4x14").
One retail source:
Two advantages I see are:
(a) pots are loongish (compared to volume), and
(b) pot sides are fluted, which helps new roots not to circle around...
[Edit: One minor disadvantage (TP49); the bottom holes are rather too
big for me, needed to place some soil-blocker; e.g., a piece of pine-bark
or just a 2 sq". piece of paper-towel]
A word of caution!
These pots will incur some more $$ expense,
and other (cheaper) proven fig rooting pots/cups
for 'normal' cuttings should not be ignored/discarded...