I am guessing it has to do with the tryptophan activated when milk is warmed. Shane, I don’t drink regular milk.
i tried it for three days, it definetly improved recall, but I didnt have any lucid dream, altough i was using autosuggestions and fruit 
but today, before sleep i ate some almonds (nuts), 2 bananas and drank 3dcl of apple juice, ended up with 2 ND with super recall and 1 LD …
now i think i should try all together and see what will happen 
but i’m pretty sure that autosuggestion is most necessary.