Not sure but if you copy the all required files for inetd to run and also all daemons and whatever they need into chroot then ammend the start up script in the real filesystem to read something like
chroot /jailedenv /wherever/inetd start (or however u start inetd)
then that should work, this is how i did it with Apache anyway so Id assume its the same sort of principal as by changing the script that starts inetd on boot to point to the chroot env which contains all daemons etc. you want to run your starting it in a chroot env.
hope this is clear and doesent sound like complete rubbish