Agree with MJR about using it on 152/172 with flaps.
I occasionally fly a C120 (no flaps) where its a valuable part of the repetoir.
I'm surprised by the comment about dropping through cloud in a slip as it would be extremely difficult to coordinate by sole reference to instruments - T&S and airspeed I guess but botth instruments liable to errors in that configuration.
I demonstrate it during the PFL lesson as one (of many) techniques to control ROD towards low key position, but only on final approach if flaps are inoperative.