Opportunity is missed by most people because it is dressed in overalls and looks like work. - Thomas Edison
Maybe try some bugspray with a high concentration with DEET. It doesn't work on all plastics, but it does melt the surface a bit on some. Just used it to clear some fogged lenses on air regulators. Can also be used on fogged car headlights. Worth a shot, esp if yo have some sitting around.
or just order some from ULINE if they have to be that clean