Being the home TV police officer is not a fun at all and nobody can survive being one for long. At some stage, you will need to make sure your kids have enough understanding and awareness to regulate their own TV consumption.
I remember realizing this when my daughter Eden was 4. She was sensitive to dairy food and I was a very good dairy police officer (I had no guilt feelings, because eating dairy food meant she would get pneumonia). Eden went to kindergarten and I knew that although I wrote on the admission forms “No dairy food”, she would take food from other kids. This is when I knew I needed to teach her to be aware and understand why she needed to restrict herself.
The TV diet works the same way. Your kids will be exposed to TV more than you think and certainly more than you can control. All my kids have come home at times with details about TV shows I have never allowed them to watch. This is the reason raising aware kids is better than fighting this on your own.