Yes, this method works fairly well. I have used it in the past. It can also be used to make body shape morphs, so that clothing can fit irregular shaped figures. Instead of converting the exported mesh into a new outfit - which you can do if you wish to use it only for that body shape, but if you want morphs. Import it back into Poser, open the grouping tool, and click the spawn props. Delete the imported mesh, and you should be left with spawn body parts to use as morph targets. Export these one at a time. I.E. hip, rThigh, lThigh, etc. You can name them whatever you want, and uncheck all boxes when you export. Next load the conforming version of the outfit, select a body part, click on Object on the menubar, select Load Morph target, and find the morph (body part) you exported for that body part.
Give it a name where prompted, and click Okay. Now when you set the dial value to 1 for the morph. Do this for all
body parts. Next zero all the dials in the Dress, including any FBM in the body section. Then set all the morph dials you just imported to 1, click on Figure on the MenuBar and then on Create Full Body Morph. Give it a name where prompted, and click okay. Now Click Edit, Restore Figure (shift+ctrl+F) to reset the default dial settings for the clothing. Now, set the FBM dial in the Body group to 1 for the morph you made, and the clothing should take on the new body shape you gave it. Sounds a bit complicated I know, but it is really fairly easy once you get the steps down.

Great post Caulbox, this should help folks who are desperately trying to get V2 and V3 clothing to work on SP3