I did a little searching and found this page:
http://www.pinguicula.org/pages/plantes/pinguicula_medusina.htm
I thought about getting one but I just read that they form an underground bulb during dry dormancy. That turned me off them.
What about P. moctezumae? What's the dormancy of that like?
I've got one, now, as well. It came with sand. What is yours in?
LOL! What is a Ping mix? That's a rhetorical question. My mix is actually Perlite, eggshells, sand, and crushed coral. I guess the common concept is something that drains well and doesn't keep the saturated. I took a picture of mine, right after I received and potted it up. So this won't be impressive:
For P. medusina I found it grew best with a loose gritty mix (2/2/1 APS/Sand/Peat) kept on shallow tray when actively growing and then pulled form tray and left to dry when dormant. Lots and lots of bright light.
For P. moctezumae, you can basically grow this in any CP mix and keep the media moist but not sodden. Some of my best grown specimens were those that I had in pots with Neps. They also did really well in my tuberous/petiolaris mix (2/2/1/1 APS/Sand/Peat/Milled sphag)
I wonder how my friend gets such good results growing this in such a different manner!
The conditions sound pretty much typical Mexican Ping.
One thing I can say about this species is that it produces prolific plantlets from its leaf tips. Mine both came in with at least six plantlets apiece. If you have trouble in one mix, you should be able to start over fairly easily with the plantlets.