User blog comment:Xilinoc/Ch. 562 - THE VILLAIN 2 (Mask De Masculine is a Mexican luchador in a German army)/@comment-24113610-20131218222834/@comment-6657474-20131218234020

Bear in mind that most Eastern cultures have a collectivist mentality, and in such societies, it's much harder to get away with doing something that's forbidden based on a technicality. For another possibility, we should examine the outcome of Mashiro vs. Wonderweis. Despite Mashiro's claim that she could maintain her hollowfication for thirty hours, her mask shattered well before that time limit was up. Based on this, we can conclude that the duration of hollowfication may depend on the power level of the opponent the Visored is fighting. If the Wandenreich Quincy are much stronger than the Arrancar, the Visoreds' hollow masks might not be able to last long enough to make a significant difference in the outcome of the battle.