We put our brats, dogs and kielbasa all in the same water. We finish off the kielbasa on a tiny griddle over a gas burner. The same griddle we heat the meat for our subs/hoagies on. You need to make sure that the food you are planning to serve works well for your cooking method. Not all dogs/sausages are good in a water bath and not all are suited for steaming.  Taste test based on how you will be cooking them!