Often we don't clean the skimmer due to the hassle of disconnecting the skimmer pump wire through the spaghetti of wires in the cabinet. What I did after the warranty ended was to extend the pump wire with a IP67 waterproof connector. Then dismantle the various parts for cleaning.
As for the pump, just dismantle & wash the parts in a bucket of water there.
Don't forget to clean the venturi valve as there can be calcium deposits blocking the air flow.
Inter-dental brushes are great for cleaning the tiny slots of this piece. This was from Daiso.
A friend was planning to put some fish in his sump & requested a skimmer guard. I printed one for myself as well.