Wow, I used to think filters were just a gimmick too. Seeing how washed out the sky can get at a place like that really changed my mind. What kind of camera setup are you using?
Did you actually try using a red light or turning off your phone for a good 20 minutes first? Half the people I know blame light pollution but they're checking their phone every five seconds. Your eyes need time to adjust or no filter's gonna help that much. What filter are you looking at specifically?