In trying to find puzzles that would solve with the Empty Rectangle stuff, I have not been very successful... However, i did find this one, where the solution is a "tiny" bit shorter by using it:

concider this one:

now you can apply the ER rule here:

and the puzzle solves instantly!

However, there are also a 2-string kite there, but then you need another few single candidates (1 or 2) before the puzzle is solved, so the ER is slightly better...

the thing I like best about this technique is that is actually much easier NOT to look for candidates, then it is looking for them

havard