Have you used mollies in a saltwater tank?

Since mollies have a special ability to move through pure freshwater, to brackish, to saltwater, many people use these fish to determine if there are any issues with their water quality in their tanks since they are fairly cheap compared to many other saltwater fish that are common in the hobby. Have you ever used mollies inside of your tank in order to get used to saltwater (as a beginner), or do you use them as a dither fish in the background since they breed extremely easily and are very popular in the freshwater hobby?