An air hole is what you punch in a can so that you can pour the liquid out without it glugging.
In principal there are two forms of CAT...those caused by shear between layers and rotor.
The atmosphere is a bit like a lava lamp with "bubbles" of air with different homogenous properties. They don't easily mix and it's the shear due to speed differences that cause the turbulence. Sometimes this is associated with temperature difference hence the aircraft can go from a sustainable altitude to one where the engines do not produce enough thrust (WAT).
Vertical shears are normally associated with thermal differences I.E. Thunderstorms.- IMHO the most dangerous as often poor recovery techniques can cause catastrophic failure.
The correct procedure is to fly a fixed attitude manually with fixed thrust and trims settings...you accept the altitude gain/loss unless you is near terra firma.
The second type is normally associated with mountain wave systems and is a relatively stationary tumble dryer like motion at low level although I have been knocked unconscious in a rotor associated with convergence.
But if a pilok says he hit an air pocket he must be right ....could be man made such as a SAM.