Should I worry about HP washing for Wild Hunters?

You'll be fine without washing, though it never hurts to do it. If you have the funds, CHTP and chaos zak helm are incredible assets to have, and because of the jaguar mount, they already have much more HP than they need.

EDIT: Also, the rex earrings? Don't use 'em. With Vulcan you BURN through the durability. They're not worth it after level 120.