Conversion therapy is just as unsettling to me in the reverse.
Calling this "conversion therapy" feels a bit disingenuous, since conversion therapy is all about gaslighting people into suppressing their true feelings, while Aya's determined on making Marika realize what her true feelings actually are. Case in point with Marika never really considering why she wants to be with men the same reason she wonders why women would want to be with other women. It's a real change, not just manipulation (even if it's still got some kinda creepy vibes going on)
You say that as though Aya is operating from a position of certainty, and is therefore justified. But she just did it on a whim, so far as we can see.