Yes. If it tells you to just place them on a strad of waste yarn, then all you are really doing is using the waste yarn as a stitch holder. Nothing more than that. Don't knit them onto the waste yarn, if you do that you'll end up frogging and possibly losing stitches.
OTN: Jeckyl and Hyde Hat, Shetland Shortwrap( )
FO: Lacey Stole, Library Capelet, Dead Fish Hat, Tree Bark Scarf