Smoke, I have never added juice in the filler material (by dripping) besides the initial fill. I have, however, done many dry hits. When I feel that the flavor is dropping off, I take the tank off the batt, put my finger over the airhole on the bottom and take in a few draws until I see a tiny bit of juice in the airhole. I then vape off the bit in the airhole and vape on. That is normal for me. I do it as a precautionary measure so I don't burn out my cartos too soon. The frequency that I do it depends on the juice I'm using. My ADV I did it probably 2-3 times a day.
I would recommend my method over yours (no offense) because if you continuously remove the DT it will wear out the o-ring and render the DT useless. But that's just me.