Chris
I have cleaned suites over the past four years that had dry clean only on, with no problems. I always ask the customer whether it has been done before and also whether they have tipped liquids on it and was there any problems.
I have also noticed a lot of suites have little tags sewn in the cushin seams saying do not dry clean yet the main lable says dry clean. I think this is to tell the householder not to remove the cushions, if possible and put in the machine. One customer did this and the colours in the rope trim ran into the white material.
As far as shrinkage is concerned, touch wood it hasn't happened to me yet. If i am unsure i always clean 1 cushion then dry it. Better to ruin a cushion than all of suite.
Dave