If this were a new housing I'd say "Nope, don't bother." As it's a used housing I personally still wouldn't waste a dive taking the housing down only, but you might feel more comfortable doing so.
You've tested it in the pool, you've carefully inspected every mm of the thing visually - I'd be happy with that
But I live on the edge with these things and it seems most people do the dry run first. I never have and likely never will with new gear.
The only time I've ever taken a housing without camera to depth was when I had what I thought was a small leak on a dive. Back on the boat I took everything apart, visually inspected the housing inside and out, did a rinse tank dunk test, then put some wrapped weights inside, tied it to a rope and lowered it overboard to our dive depth. Left it there during the surface interval and pulled it back up. Stuck the camera in and away I went for dive two with no problems.
Now, there
could have been a leak through a button when pressed that I wasn't able to test by just dumping the thing overboard, but it was a risk I was willing to take.
Just be aware that taking your housing down empty does not mean that a flood will not happen. It just means that no flood happened on that dive. Floods are almost always user error of some description so the more times you do it, the closer you are to yours
