The only reasons I can think of to wash the nib unit on a regular basis would be: 1. The cap is not sealing correctly against the pen, letting the ink dry in t

The only reasons I can think of to wash the nib unit on a regular basis would be: 1. The cap is not sealing correctly against the pen, letting the ink dry in the nib and feed 2. The ink is not water soluble, so if it does dry it cannot be fixed with a water flush But these two problems were mostly solved 70 years ago.