Read your filter manual before attempting anything like that. But, in general, acid cleaning cartridges and DE septum membranes is more likely to cause irreparable damage, than to help. If you do acid clean you MUST clean with detergent (TSP) first!

Regarding your filter stopping up . . . what is the condition of your pool? If there is ANY algae, you must kill it before you can expect your filter to work well. Live algae plugs DE filters very, very rapidly.