This is not an uncommon problem that has been covered many times, I'm sure.
Am in my third year of diving and it seems as if I spent my entire first year figuring out how to solve the waterlogged ear situation. My first dive trip for my OW cert resulted in clogged ears that turned into an ear infection that required a doctor's visit, some antibiotics and ear drops to knock out.
Experienced divers turned me on to a homemade earwash made up of 1/2 distilled white vinegar and 1/2 rubbing alcohol. Use it the same way you use the Swimmer's Ear solution and it should help. Now, my procedure after every dive (while still on the boat) is to flush with Swimmer's Ear, then use the vinegar/alcohol solution when I get back to the room. Basically, I let the solution sit in each ear for a few minutes then let it drain out. Sometimes repeating the process. Might be overkill but I tend to over do things anyway and it has helped tremendously.
The other thing you can do is take note of which head positions tend to cause your ears to fill up and try to avoid them. For example, if I do a backward roll off the side of the boat and flip completely over, my ears will fill up. So, now I make sure I don't flip completely over.
If you are prone to ear problems you may not eliminate them completely but hopefully these ideas might help.