I know that you think that Exalted powers are just magic easily identified and countered and that the white court are omni competent, but the reality is that our Exaltation is every bit at bullshit as Nemesis and was made to fight things even more bullshit. If they didn't notice Justine being inflected by Nemesis they aren't going to figure out anything about how our maggots work.
And even if they did a minus 1 DC is not such a bad thing. A much worse thing would be to make a potion that feeds the hunger and allow it to fall out of our control and cause havoc.
That's a lot of words to put in my mouth.
To start, I'm aware that exalted powers have more going for them than mortal magic. It's just that other people can do stuff too. What that means changes with context.
Charms have properties that can be at minimum observed, even if they're not possible to stop from acting within the confines of their function. People have different skills sets and perspectives which influence how they can and will approach things
In the case of the white court, it's not Omni-competence so much as it is that they're old, paranoid, and well established.
Tricky effects slipped into food are a classic, and checking if they explicitly magical stuff you're about to eat has a fish hook in it of some kind is a basic precaution. Especially when it's a serving of fat hell maggots fed on a steady diet of souls.
The comparison to nemesis is just silly. Nemesis is an active infiltration agent with plans and the willingness to wait to strike.
MMP is a fire and forget persistent alteration.
Nemesis is a stealth jet, and MMP is an ice cream truck. We could probably develop a killer stealth jet if we wanted to, but that's not what this charm is supposed to do.
In terms of consequences, I'm not sure what you're getting at.
Why do you think the white court would shrug it off as no big deal?
If our hypothetical alternate recipe got out, what damage might it do?
Not that I'm saying it's impossible for it to do harm, but you seem pretty adamant that it would immediately explode.