what moroccans call sheeba is Artemisia arborescens.
I can tell you that because my wife is moroccan from Oujda and in winter, when fresh mint is not available, they use sheeba instead. They prepare green tea as usual, but instead of adding fresh mint in the tea pot, they serve the tea in glasses and present a glass with small branches of sheeba, they take one and stear the tea in the glass with the branch. Depending on the strength of the taste they desire, they leave the branch in the glass or not.
If you are sure everybody likes it, you can of course put one or two branches in the tea pot but the tea can turn bitter if you leave it for too long.
I hope this will help you despite of the time that has past ince you posted your messages.
Be careful though, this plant is of the same family as absinth ...
It may have abortive properties.
Here is a link to an online french gardenshop, just to give you an idea of what it looks like.
I bought mine in a garden shop close to my house.