what i like to do with my sidechain sometimes, is make the compressor a look ahead compressor.. it can smooth it out sometimes.
make a copy of the track in your DAW
one copy is going into your compressor/limiter
the other copy is going into the sidechain input.
now just push the copy going into the sidechain forward 2ms or so.
sometimes for some de-essing i might use the sidechain too..
i'm going to try your method this afternoon as it seems to be a nice sudo-multiband trick
as i really don't like to use multibands