Product review (4 stars): Works as they are supposed to.  Not worth trying to clean really dirty old ones.
I recently bought an older home that has a non-ducted Broan hood.  When cooking the first time, the smell from the hood was disturbing.  I actually put the old ones in the dishwasher -- not worth it.  They were a mess.  I ordered the new aluminum filters and the charcoal filters.  After getting them installed, everything is fine.