Drywall Dust Everywhere

I have a client that had a computer room built in the corner of a much
larger and unfinished room. Separate Power, AC etc. Well it appears the
room has negative pressure compared the larger outside room. And after
several days of dry walling, sanding etc etc, a lot of that dust got sucked
in to the room and the computer gear.

The Power8 itself has really good access to its insides. So no problem
there when it comes to cleaning. They also have a couple of V3700s and
expansion trays. Never physically tore one of these down. Can we pretty
much get to everything by powering, removing all the disks and cans ( care
to note locations etc ) that we need to clean these guys out?