Akane, that's not what Kaiba means by 'screw the rule'
Not just brainwashing, it's reality bending/concept altering.
It's dangerous af tbh, to be able to messed with both the realm and its god is too way overpowered even if it's just a harmless change. Like imagine, reversed concept of cured and poisoned.
As shown though, the people eventually reverts to the 'old' way.
So while she did change the rule/ the people's perception of it initially, eventually their logic brings it back to the sensical choice.
Also this seem to require more power than Akane herself could hold so unless she forms a cabal for reality fuckeries I don't think that's gonna be a problem soon.
Even the time stop incident was not a spell about time stop, but rather a summoning of an entity who could stop time.