Ya want hydraulic lime not hydrated and no cement in the mix and 5 to 2 mix sand lime. Rake out joints dampen down and point away. I mix the line with water in a bucket first then put in the mixer with sand. I reckon it helps stop getting white patches of dry in mixed line in the motar. Depending on what finish you want on joints either take back slightly and brush down with a churn brush or finish with trowel of your choice.