You can only split the lens from the body if they are euro lights. DOT lights have asolid glass unit, that you could clean through the bulb hole if you had a big enough Q-tip. But if they aren't euros you aren't going to get the inside very clean.
Another arguement for euro lights.
'73 280SEL 4.5 (9/72)- RIP
Only 8,173 units built from 5/71 thru 11/72
'02 CLK320 Cabriolet - wifey's mid-life crisis
2012 VW Jetta Sportwagon TDI...at least its a diesel
Non illegitemae carborundum.