I haven't seen the cockpit area, but my guess is the fix for the long term is to trim the canopy down, redo the cockpit area by making sure it's closed up tight so no more particles enter the canopy. Then put a new canopy in place.
Just a guess, but normal flying use, vibration, plus the model being jolted on landings and maneuvers will probably loosen that stuff again and again over time.
If the fix isn't permanent you might have to repeat the cleaning.
Removing the canopy may sound like a big deal, but it's also an opportunity to re-detail the cockpit if it could use it.
Lastly, and the quicker fix, you could scratch the canopy up and paint it. Blue seems to be a popular color and done nicely, doesn't distract from the model.
You see many painted canopies.
Good luck.
CB