Right , I followed the hope tech video, remove freehub to clean it up and relube. they say smear a small amount of grease around the serrated inner of the hub, which i did . Popped the freehub back on and when the wheel spins there’s only a faint clicky noise from the freehub instead of the usual pronouced clicks. It works perfectly fine other than that.
Is there a specfic type of grease for this? i just used the stuff i had to hand or will the crisp sound return as the grease wears in?

As long as you haven’t overfilled the space, the pawls will push excess grease away over time. I use Rock n Roll Super Slick as it’s relatively light but is tenacious enough to stick to everything it needs to stick to.

Thats normal, serviced both of mine many times, they are always quieter after greasing, they will slowly get a bit noisier with time. FWIW I use a light semi fluid grease, which never comes out of the hub seal, and keeps the hub innards well lubed and quiet(ish)

something not too sticky is great, click will return.