I want to update the colour of the exterior wall of the whole house. I have a fibre cement horizontal lap siding and it needs updating (35 years old house). I read that water blasting is a no-no on fibre cement cladding. But the painting contractor (with good reputation) I talked to told me that water blasting is needed for the preparation. I even asked if low pressure or soft wash but he told me that it'd be hard water blasting. I'm on the end of my wits because this article is saying otherwise:

https://www.envirology.co.nz/water-blaster-water-injector/

Any ideas thrown are appreciated. Has anyone any experience with painting their wall with the same cladding and what did you do for preparation and how did it go? I had the house washed for the first time 8 years ago and water went inside through my shiplap ceiling. I found water dripping on the mattress.  That put me off from doing anything anymore. I was thinking I was causing more trouble than maintenance.