These heavier threads can be used for handwork and machine stitching with the proper needles and setup. Use one strand of 12 wt thread for handwork like embroidery. The thread has a tighter twist than either pearl cotton or DMC embroidery floss and gives a beautiful stitch. Every manufacturer makes their thread differently and so the effect is not the same from one to the next.
The pouch pictured below was topstitched with #12 wt thread on a sewing machine. Use a size 100/16 needle and test your tension prior to stitching. Use a lighter weight thread in the bobbin. Topstitching Needles have an extra large eye and might be a good choice for this thread application.
Pouch constructed by Judy J. in a class given by Barbara D. Both are Moonlight Quilters Guild members.