I haven't bothered to, no. Just leave it filled in.
Depending on what you're using, hollowing it back out may potentially break the items, and I've found that virtually no one:
A: Knows that part should be hollow to begin with
B: Inspects the items close enough to notice
C: Has the proper viewing angle to see that part.
It's hardly noticable (the one in the foreground obviously not hollowed if you know what/where to look, can't even tell on the rest if they are or not):
