Tom Sensei i agree with you. Chiburri was definetly not oractical enough for the purpose of removing blood from the blade, thats why the bushi had tenugi. Chiburi when done as a cut properly requires Tenouchi omce the blade is in feont of you. Otherwise its a bad cut or a bad chuburri.
Fantastic , this explains a lot , in previous kendo and kenjutsu practices I would stand for O Chiburi and then make the cut, but I prefer the way you describe it here ❤️