If the behavior is not desirable, don't permit it.
Stop Koa immediately with a loud "NO" accompanied by a physical touch (NOT a hit or smack, just a firm touch) to the shoulder to physically snap him out of it.
Redirect him to a chew toy or other allowed item and give praise when he engages the other item.
Be consistent and don't allow the behavior sometimes, yet not other times. If you are consistent with interrupting the behavior, it will eventually cease. If you are not consistent, it will never stop.
Ok thank you. that's good advice.... I'll have to be more serious with him from now on.
Our old dog Chica was most diligent at ear, eye and general face care for her pack mate Maggie. Two or three times a day, Maggie got the full beauty treatment and loved it! If she got tired of it after a few minutes, Maggie just got up and walked away. No hard feelings. The sad thing is that after Chica died, Maggie's ears started getting full of junk, so now we get to do the job at least every month. We sure miss our Chica Pet. :-)