A piece of a roll of camera film can sometimes be carefully slipped in between the seal and the shaft at an angle (a slightly out-of-square cut helps) and then drawn carefully back out in a roundy-round kind-of motion to straighten the lips of the seal (or possibly wreck it permanently if you are not carefull as the film is sharp!) Or draw out any remaining material. If you can see in there, use a light and a magnifying glass and tweezers to get every little piece of that net out (at least I need the light and magnifying glass these days, lol).The little cutouts in the film for the feed wheels of the camera can draw out dirt and/or debris. This sometimes will fix a seal forever and sometimes not. If it still leaks, that would be my next attempt. I have an old roll of film around just for that purpose. I keep it around for the next time...