Not quite like that. I usually call the method you mentioned "plinking" since it's so prevalent in SF series. Plinking doesn't seem to work at all now, even for iMCF.
For the new ear slicer, you need to press and release A *very quickly*. I find it easiest to rest my fingers naturally on A (index), B (middle), K (ring). When I plan to attempt do an ear slicer, I will move my index finger down to the very corner of the button and try to flick the edge of the button. It's sort of like you're intending to push the space between A and G and brush the button on the way. This is the same method I use for Just Guard.
So once you have that corner-of-the-button-flick thing down, just press B+K as fast as you can. Try it in trainer - the first few times you do it, you'll probably get ABK all vertical on one line. Then you'll probably start getting white A then black A. After a few tries, you should start seeing a white A to the left of B+K with that beautiful URASAI! shout from Yoshimitsu. Or "Quiet!" if you have it in English.
Oddly, if you get good at doing it this way..... you can just do the exact same input (including the K) with a 2 to get iMCF. CH Ear Slicer links to iMCF for big combos now. The input notation would be something like a:B+K 2a:B+K 3B 6K for one of the weaker iMCF links.