There’s been discussion about this exact thing before - I’m not sure if anyone actually knows what that means, and I bet most people who have made a booga bag has just picked up stitches as usual, the whole way around, and not had any problems with it. That’s how I did it and my booga bag is very functional and sturdy. Felting takes care of everything anyways.
If you knit a twisted stitch it just turns out a little tighter and is supposed to make the bag sturdier. Not critical at all though, plenty of people have done it the “regular” way with fine results.