I just went through this with Mishi - serious wax build-up in just one ear. The vet prescribed Pan/Cer - an oily liquid, that I put in his ear, massaged it down into the canal just like described above, wait for the squishy sound to know you've got it down where it's supposed to be and then mop up the excess with a clean cotton ball. Be careful! Their little ear canals are DEEP! A couple of times I was surprised how deep that cotton ball would go. The stuff is oily so his fur got a bit messed up for the prescribed 7 days of treatments. A good wipedown with cat wipes got rid of it and now he seems to be fine - no more airplane ears!

The first time I heard of "airplane ears" was when my vet first cleaned his ears. Cracked me up too!

You can probably find over-the-counter cat ear treatment stuff at Petco. Good luck!