Not really.

It is sometimes possible to export a conforming item as an obj and then reimport it to use as a dynamic, but often the item falls apart, even if you weld all the seams. It's worth a try, but don't be surprised if it doesn't work.

It is also possible to use a conforming item by choosing one part of it, and running that through the cloth room, but this is only effective in limited applications, such as making the skirt of a conforming dress into a dynamic figure. Again, it's worth a try.

To have high confidence the cloth room will work, you really do need to use dynamic clothes in it. There are a number of them out there for free. Google "dynamic clothing poser v3" and see what all you find.