Huh, I always say hi regardless of whether it's leisure travel or I am commuting to work.

Jumpseating: "Hey, guys if it is ok I was hoping to ride along in the back/up front here with you guys"

Non-revving: "Hey guys, I am non-revving on this flight if it's ok with you"

Everyone has always been nice and usually say "Thanks a lot for saying hi"
I feel thta always speaking to the pilots helps to foster the fraternity which I feel is unique to our profession. It's nice to shoot the **** for a few seconds too.
Furthermore, as far as I am concerned, if I am flying for free my presence on the airplane is entirely at the discretion of the captain.
I have been doing it for less than a year though, so I am still comparatively new, but I always feel more comfortable knowing I said hi to the flight crew.