https://dynasty-scans.com/chapters/sorry_but_im_not_into_yuri_ch24#17
did she offer aphrodisiac tea to the spirits
She offered tea spiked with the 'Love Poison' she got online. Which has had distinct effects on people as compared to the aphrodisiac she herself was given by Arare and probably has a supernatural element to it, given that ghosts are totally a thing.
What has me curious, especially on skimming back through is what exactly Ouma saw about Toudou that concerned her. The two thoughts I have is that either:
A: the Love Poison, being a supernatural thing, incurrs some kind of spiritual effect on one who would choose to employ it against others, like a minor curse or karmic debt (this might be why the slapstick and woe of Toudou have fallen by the wayside as she has stopped using it). Consensual or not, whether it changed anything or not, she did use it on Mukai shortly beforehand.
B: the evil school conspiracy has an occultist among their members/leveraged subordinates and threw a curse or something onto Toudou rather than take direct revenge against her. For unknown reasons she was resilient/resistant enough all it did was get her a bit sick.