Only select few gearboxes have metal screen as filter, almost all others have a paper filter media, do not try to clean those.
Another stupid issue I used to get asked a lot in Pakistan was, "shlicone packing se aap kyu nahi chipkaate", pehlay banday ho jo asli gasket daaltay ho hamesha.
Using generic orange silicone rtv is not a good idea on any part of transmission.