Ras el Hanout is a basic spice mixture in Moroccan food. Every cook seems to have his/her own blend, but traditional ones have as many as 50 ingredients (although 15-20 is more common). Many of the "authentic" blends include items that are thought to to be aphrodesiacs.
I'm not aware of anyone using it as a marinade, per se. But can't think of any reason you can't.
What are you thinking of using it with?
Most people spoil garden things by over-boiling them... if they are overboiled they have neither any sweetness or beauty. Hannah Glasse 1745