Go for it!! Some people thrive doing things over their heads. Sure you can use straight needle to do two handed fair isle. I didn't go to look at the video (my computer is too slow for easy video watching) so I don't know what kind of technique they were sharing, but I have done two handed fair isle.
Can you do it knitting backwards? I never have, but I suppose you could. Keep track that you have the floats always on the back. Knitting backwards will give you "normal" untwisted knitting if you do it a "normal" untwisted way. I suppose you could do it twisted as well, but I never have.
Whether the result will be an ideal dish cloth? I don't know. I suppose any knitted cloth can snag under certain conditions but you could still do it. You could also use it as a face cloth and not have so many opportunities to snag.
Have fun and learn a lot!