I'm not familiar with the type of obscure trick you're implying.

However, I could give you some advise on how to do something similar. Bash has a mode in which users shall not exit their home dir (RESTRICTED MODE). This mode can be activated by calling bash with another name (rbash -- which is simply a symlink to bash) or doing bash -r . Although this restrictions work fine under normal usage, they are only a barrier to dummy users because any programmer could bypass them all.

Alternatively you could try more reliable methods such as virtualization (f.e. xen).