Preheat the oven to 350 degrees Fahrenheit. If you think of it, move a rack to the middle of the oven. No big deal if you forget.
This is going to look and feel so very wrong, but trust me it works. Hold the bread cut-side down and let the water run over the entire baguette for 10-20 seconds. You don’t want it sopping wet–just damp enough to absorb the moisture lost when the bread went stale.
Promptly place the baguette directly on the oven rack–no sheet tray necessary.
Depending on how wet your bread was, it should take 5-10 minutes for the baguette to warm through. As the bread heats up, any excess water will evaporate leaving you with fluffy warm bread and a nice crisp crust.
Remove the baguette from the oven, using tongs or an oven mitt since the bread will be very hot. Slice and serve!