Execrations usually get lumped in with curses. Which I can see why. Execrations are used to magically destroy something. Pagans who follow the misinterpreted "harm none" or the Three-fold Law tend to think execrations are a big no-no. There are even some Kemetics that still use the "harm none" that are against them.

But! Historically execrations were used daily (there's even a theory that it was multiple times a day even) in the temples. They were used to destroy Apep or anyone/thing that threatened ma'at.

They can be as simple as forming something in the image of what the person wants destroyed (then using heka to make it that thing and destroying it) or to the elaborate rituals in Eternal Egypt. Usually it seems like Kemetics will only perform execrations for Wep Ronpet. But that's usually because of the "universal ethics" of using curses.

Sources:
Kemetic Roundtable
Devo Magix: Execrations
University of California