Dot and dab external facing non cavity wall

[Daveo82]

Hi guys plasterer has said to dot and dab external facing wall - take back to brick then dot and dab straight onto wall as sand and cement would take too long to dry and we are in a bit of a rush - cannot create wooden batons for board as we are too tight on space - I am worrried as most forums say you can't do this can anyone give advice please