Adding a gallon of good gas to a gallon of bad gas... makes 2 gallons of bad gas
Draining the tank is a good start, but unless the tank is DRY afterwards, all thats left in the bottom
below the drain is now just water. Engines can run on a surprising amount of water in the gas and the Heet you add will emulsify the water (allowing it to be digested by the engine) BUT your fuel lines and injectors are now so full of the bad stuff, the bike won't even run, right?
1) Lucky for you the fuel line and injector rail on an XB is pretty short. IMO, pull the fuel line
at the rail and cycle the ignition a few times (run on) to purge the supply line, use compressed air to blow what you can out of the rail, re-assemble (the WHOLE bike), cycle the ignition a couple times again, and you have a shot of it starting relatively quickly. See #3
OR
2) At least drain the tank, add the Heet, then add a gallon of gas (less is more here), slosh the tank, put your charger on the highest setting, and crank away... Let the starter rest for a couple minutes for every 30 seconds of cranking.
3) Once its running, leave it running, and go ride it
a long way to a gas station, the movement helps it mix and you want that gas out. Even emulsified gas can rust internals.
Bonus point for using the Ol' Gloomshadow trick and add an OZ (more is not more here) of 2 stroke oil to the tank at the gas station, just before filling it. Opinions vary, but I have personally seen the benefits in a very non-scientific and un-proven ways. IMO, it can't hurt anything in normal doses, it mixes with gas, and it should combat water damage.
That should be all you need to have a fresh gas system. No need to replace pumps, filters, or socks from just a short bout with water intrusion. Once flushed, they should be fine.