I clean them every day. Now, by "clean" sometimes it can be simply getting a tissue and wiping out any excess gunk i see. So not necessarily putting in the ear wash and all that. That may be once a week when it's more of a "deep cleaning".
Ugh, Brutus is prone to ear infections so I try to at least squirt the ear wash into his ears. This is while I'm trying to wrestle him down while he is trying to eat me!! Sometimes I try to sneak attack him while he is sleeping. Of course, it never works and I have to run for my life! He hates having his ears done as much as his nails!!! Frankie's ears are always clean so I leave him alone, but I check him daily.
We officially do the boys ears with Vet's Best every week to 2 weeks, but they do daily maintenance to each other so even waiting that long there usually isn't much to clean out Super cute to watch them take turns on ears lol