So, what you can do is one of two things:
Create network home directories, so that one home folder follows a user from machine to machine, but doesn't install itself on the machine itself.
or
Script a solution to delete out any user data at a specified interval. Be careful not to delete out the local admin account! You could always move the local admin account to a different directory (not in /Users) and update the Netinfo record to reflect this move. Then you could just have a script that deletes everything in /Users on a cron task, like every night at midnight or such. If you don't want to move accounts, include in the script to check the directory name and as long as its not the admin, delete it.
hope this helps
Michael