I would never use an over the counter/pet store ear wash on a pet. If you need to clean the ears- you need to see a vet as it indicates a problem that needs to be addressed and that OTC ear cleaner will not solve. Depending on the ear issue- some cleaners can not be helpful at all. If the ear drum is ruptured- you need a special ear cleaner. Moisture can cause infections- and if the cleaner does not have a drying agent it can CAUSE an infection to start. Some pet stores ear cleaners can be painful (like alcohol on a cut) and make the bunny scratch his ear and make the problem worse or cause a problem.
So I really do not recommend over the counter ear cleaner. You should not have to clean your bunnies ears unless directed by the vet. I have never cleaned my lops ears- if it is not broken- don’t fix it.
But if you ever do wipe out your bunnies ear- no Q tips– just put a tissue or cotton ball over the end of your finger and wipe the ear out. Your finger width and the anatomy of the ear canal should not allow you to be able to get deep enough to rupture the ear drum (which is painful and another problem).