http://dds6qkxpeiqvogt4y2fd7vtsxq6pvokekb2h4la7jd4iwl4ljuawu5qd.onion/wiki/Live_Mode
From the second time Whonix-Gateway is started onwards, it is the user may opt-in to run it in live mode if non-persistence, amnesia is desired. This should eliminate any Tor-related cached data like DNS requests that could leave traces about web activity. However, be warned that it may make your Tor behavior distinguishable from that of regular Tor users, which could weaken your anonymity somewhat.