Hidden volume plausible deniability is neither useable nor robust.

1) File creation / Access Times

2) The oppressive regime already has root on your box.

3) The oppressive regime already has a camera trained on your box.

4) All operating systems are dogshit.

Use LUKS. Disable your wireless. Never loose physical control over your device. Nothing says plausible deniability like a pile of Carbon... 

-Travis