Finally the penny has dropped!
I was looking at a previous Guardian Prize thread and saw this again, realised I hadn't solved it, and so set about having another go.
I think my earlier attempts all ended in failure because I'd convinced myself there was a T in it from "close to sweet".
Looking at it again today with fresh eyes, and having disavowed myself of that notion, I finally noticed the reason why Malone might appreciate this particular clue.
Anyway, I got there eventually and, yes, it is a good clue π