Do you know why the Brits call the bathroom the 'loo'?
Or why they call it the water closet?
The toilet was essentially in an indoor outhouse, with water. Very observant people.
Loo comes from the French...'l'eau', meaning water.
Over time, "To the l'eau" was said faster and faster,
Eventually becoming "Toodaloo"
Therefore, when someone is departing your presence and signs off with "Toodaloo"
You should laugh and say, "Thanks for sharing!"