bamberger, I would suggest that the most intuitive way of solving a cryptic clue is to think of a synonym for the definition (the number of letters and words gives a strong indication) and see if you can get the subsidiary part of the clue to fit it - and so whilst checking letters are useful ,they are not necessary.
At least that usually seems to be how my mind works if I analyse just how I solved a clue.
And no, I'm not aware of that being a regular clue; that's the first time I've seen that particular one (as far as I can remember)