Lick and a Promise
This is originally London slang and quite an old expression; its first recorded use is in 1838 in an English newspaper (The Era) where it was used to describe a uninterested or half-assed attempt at any sort of task or job. Gradually its use changed until, by the time The Era closed in 1939, it was used and still is used to describe a perfunctory wash, less thorough that even HF-AGBA, a BBA or an airplane bath.
Malcolm’s really stinking this morning, I don’t think he even bothered with a lick and a promise.