Hi I was in Chefchaòuen 2 months ago, beautiful place to go in Morocco for sure...
There are lot of people that ask you if you want hash ( everyone has the best quality , they say :-) ) , and they want to show you their farm full of plants .
If you want to take it easy take a room to Hostel Rif for Anyone.
It's a Hostel managed by a Scottish family from 2007 , smoker friendly , and cheap , I smoke with them ,and I easaly purchase 1st quality hash paky/Maroc genetics from them for about 2 Euro / g , that was one of the best hash I have ever smoked. Go to tripadvisor site for more info.
Otherwise you must know the right people , if you want good quality and price , searching in the centre , lot of people offers pollen light pressed of med quality,
the other good way is to go in ketama by taxi to visit the farms