I would not use any Japanese condoms. They're just too small for our huge Canadian vaginas. Also, stay away from Chinese condoms as the melamine additive can interact with the vaginal flora and, if the PH is too high, can cause toxic shock, which can be a mood killer.
I use Resinite. It is an "all purpose film", comes is a 2500 foot roll (762 meters) and can be purchased at Costco for under $15, including taxes!!! That's the equivalent over 6000 cut condoms (yes, I did the math), and no sharp razor blades or scissors to handle!! (always safety first).
It has a high PH tolerance and as a bonus also protects against low Alcalinity. Because, we all know that the real culprit is an Alcalinity imbalance... which throws off the PH and then all hell breaks loose!
You should wrap the Resinite completely around your head two or three times prior to performing cunnilingus. This will assure a germ-free, flora-free, PH-&-Alcaline-Free, and air-tight barrier between you and your partner, ensuring that there is no transfer of fluids or bacteria whatsoever.
With this new knowledge and tools, you'll become the talk of the SP community in no time!