Hmm I think they will attach, but I'd be worried about the difference in weight between the usual cobra heads and the LED balls.
I don't have either so certainly can't say for definite, but my concern would be the attachment bits breaking or deforming because of the extra weight and G force they'll be under when spun.
You could get some
chains off here -
these cord ones are cheap and would do the job, or you could invest in some better ones that you could attach fire heads to.
Could be wrong though about the cobra cords not being suitable, so hopefully some other people will post as well
