I got your private e-mail too.
The grease originally put in the manual furler (mainsail or mizzen) is silicone grease, rather sticky and water resistant.
The furler is rather resistant to water ingress but it is true that this "anti dust lip seal" on top of it is important.
The lip seal at the winch handle nozzle is important too.
During a survey, I always test the manual furler separately, mainly to check if there is not too much resistance that could disable or overload the electric furler.
This test should be done once a year, just to make sure the manual furling is easily working.