About average in difficulty, which is not terribly tough.
I had never heard the phrase "done and dusted" but it seemed to fit better than other options.
Anagramming the first two words of clue 13D was one of the most difficult anagrams I've ever solved (eventually). I was thinking the wrong part of Europe.
In 20A, I have the most obvious answer, fitting the crossings, but I don't see its connection with the word "advocaat" in the clue.
What in the world is that word (Afrikaans? Finnish?) doing in the clue?