Remove any plastic packaging from your eucalyptus.
Gather the branches together and tie them tightly at the base with string.
Using a second piece of string, tie the bundle around the shower head between the wall and stream of water.
Turn the shower on high and let the steam fill the room. Take long slow breaths until you start to notice your congestion dissipating.
Leave the eucalyptus in the shower for up to a week (or until it starts to dry out and fall apart), then replace with a fresh bundle.