Well, that is true about Ol' Dirty, and it is a good point. I should have elaborated: every time I come home from the range, I like to clean my weapon thoroughly to minimize the chance of corrosion.
With my M14, I scrub the barrel and flash suppressor, use a toothbrush on the bolt face, and wipe off the old lubricating grease before replacing the grease. The trigger assembly and gas system only require cleaning every 2-300 rounds.
With the FAL, to get it good and clean required cleaning the barrel/MB AND the gas system, and wiping down the bolt/boltcarrier. Cleaning the lower receiver was as-needed. That gas system took a good long while -- BUT, at the end, you knew it was cleaner than an AR upper receiver would be
So, they both will function even if it is a LONG time between cleanings; however, it takes me 30 mins to clean the M1A after each trip to the range, compared to 1.5 hours with the FAL.
YMMV. Having owned one of both, I would go to war with either and be perfectly happy.