I just do the F5 method.
Never had any issues with fuel washing the air filter oil off. Have had numerous issues with people who haven't routed the breathers up dropping into a creek and the engine snuffing out.
Have had several issues with water levels higher than the airbox, or the bike 'somehow' going below the surface..
Crankcase drain bolts on the gasser has proven a worth while venture. Not sure why other manufacturers haven't done the same.