it's doable, the most difficult is not to get in the quad sprinkler, it's to get out, because once you have 4loop on the diabolos the loose speed very quickly and it collapses before you undo them all
i think i have the jako's video somewhere on my hdd, i can try to find it if someone wants to miror it for some time.
btw, i was thiking, would bearings help in this case? would the sprinkler last if the axes are not spinning? With bearings the diabolos would not speed down, but there would be less friction with the string and less centrifugal force to prevent the sprinkler from collapsing. would it work like this or am i totaly mistaken ?