Hughes 500 consider this - if, just if a christmas tree joint fractures or a blade goes for a walk (as it did with me one night over a city) and god forbid you had to land - causing serious injury to third party or your pax - you had better be ready to argue why you didnt find the need to follow the maintenance manual re: comp washes (including using deionised and not tap water.
The same applies to the manufacturer who refurbs your compressors - what would you do if they told you that due to you not following the maint manual, your warranty was null and void?
Shabby operations methinks...........it costs peanuts and 30 minutes to do a comp wash.....