I'm not sure, but let me call Uncle Sonny in CA
& I'll get back to you on that one.
I called 6 sources from those who grew up,
in the 40s thru the 60s.
My sources range
from an aging Hell's Angel
to a very old ex-Madam from Nevada
to a former drug lord from San Berdoo, recently released from Soledad Prison on the West Coast
& a few other strange ones in between.
All sources say pretty much the same thing,
first of all they all agree,
Hunter Thompson knew way too much stuff
and anything he didn't know,
he made it up, presented it as the truth
and made it quite beliveable.
Second, that when you roll your own weed,
twist the ends as not to lose a precious bit of the stuff,
when it gets down to where,
you have to use a hat pin or
such to be able to smoke that last bit,
the butts do look like baby cockroaches,
but not the big black ones that most people
associate the word "roach",
but the small brown ones that are often referred to as "German roaches",
because of their color and striations
of cream colored spots.
Rolling papers take on these characteristics
and the butts often do look like those wretched little insects.
Sources are listed within my answer.