Then ponder why Itachi didn't do such a thing.
Not only that, everything has to be exact; both times where Itachi cut off his horn were complete replicas, something that can't be guaranteed if Kabuto's the one who's attacking. Plus, if he's figured out that it won't work the first time, why would he do the same thing? Itachi has to be the one who's inflicting said sensations, not Kabuto.
Itachi didn't stab himself with a sword twice, now did he? He forced kabuto into repeating what begun the link.
The reason he didn't use what I'm saying is because kabuto never wrapped him in snakes. Itachi initiating the loop on a sword stab because that's the first time during that entire bout that kabuto landed a hit on him. Therefore, itachi chose that moment to begin the loop instead of wasting time to force kabuto to do something else to allow him to initialize the loop. After that point, all itachi had to do was waste some time until he could create a situation where he could close the loop.
Bare in mind, the only time kabuto actually used snakes in the battle was at the beginning before itachi even thought Izanami would be necessary, as kabuto hadn't yet entered sage mode or even hinted at him possessing it. After which, kabuto promptly entered SM, used white rage, got cornered by sasuke and itachi and was pushed into a situation that could begin the loop (the stab).
It's that simple.
