I'm not sure if there's a direct connection between tear stains and the ear wax. My vet has recommended that I clean Finn's ears with an ear wash 1x/week b/c he also produces a lot of that brown gunky wax , especially in his rt. ear.
As far as tear stains, I have noticed a decrease in stains in my boy Tate since i've eliminated his treats b/c he recently had a GI ailment. I was actually pretty amazed b/c Tate had a very bad tear stain problem, particularly in his left eye and the vet was thinking he may need eye surgery d/t some entropian he had which was contributing to the tear stains.
You may want to do an experiment with Rocky and if you give him treats, try eliminating them for a week and see if there's any improvement.