When I smoke lamb, which I do frequently, I always marinade the lamb in different spieces (Garlic is very important) and strong beer. I prefer to use dark beer like stout or ale. The lamb has to rest in the beer (all meat covered in beer) for at least 48 hours in the frigde. I then smoke it with hickory wood chunks, until the center reaces 160 F. That will give a tender, non-wool taste. In fact it tastes better the day after, either cold or just heated on a frying pan.