I have never had any luck smoking wetter shishas using the "contact" method.
I do contact smoke Nakhla sometimes when I get a random hankering for a cigarette.
foil sticking is normal doing it that way... I would suggest rotating your coal more often doing this.
Nakhla 2XA and Peach are the only flavors I really cared for, myself.
El Hennawy (spl?) can be smoked well this way too.