Being at or near a toilet when timer has begun is highly recommended. Anyone who has seen explosive diarrhea splattered on the walls of a fast food chain bathroom stall has beared witness to a blown or neglected sequence.
At T minus 10 seconds you basically have time to remove your belt and pants at which point you must be pointing into the toilet with your anus or risk a meltdown or massive cleanup.
Guy2: We're almost there in 5 minutes, man up you pussy.
Guy1: Launch Sequence initiated...
Guy2: Look! a McDonalds!