The person is saying about the availability of k&n air filter and not about the availability of K&n air filter oil. I dont know about your bike but recently I used zic synthetic gear oil for the oil filter (red daba) for my 125 and the results were great as previously I was using total gear oil that was quite thick compared to zic one. The bike pick has increased a lot and it feels very light when revving
Xufiqar told on some thread to use 2-stroke oil for air filter as thats the best for oil filter, but I have not tried it yet.
Any how please inform if you find the air filter oil.