How exactly is this different than how tor works?
However you could use it with Tor in just the same way - your Tor-networked device should be talking on only specific network ports and any other "chatter" should be considered a leak ... so you would configure the "slug" to only allow the Tor-generated traffic on the expected ports.
I do not use Tor and don't have specific ports/protocols information on it ...
Where leaving no traces on a device is key, Tails is better, because it runs in RAM and wipes everything during shutdown.