Before I re-homed my pleco, she did a great job of keeping algae off of plants. I put plants in pots full of gravel so I can rotate them to my very bright 20gal when they look puny. Have you considered (sounds a little crazy) trying to wipe them off a bit with a clean cloth that has soaked in a bucket of tank water overnight? If you're sure there is no soap residue involved, I don't see how that could make the situation worse. . .
Thant actually makes sense. I did notice that it wipes off pretty easy. I think tonight I might try your bucket idea and wipe them off in the bucket rather than in my tank. I was also thinking of adding some hydrogen peroxide in the water. Will post some pics afterward.