Here is more information from the shadowy and shady realm of practitioners.
This Inconvenience advertises a poison dream formula, and its text includes a testimonial.
The formula has been found to effectively poison dreams for any length of time from one day to forever, the ultimate goal.
Smith’s Effective, Module Formula for Poison Dreams
A Testimonial
In the day, he complained of pain.
He said his dreams were bad all Monday and Tuesday and Wednesday,
and then, as far as could be ascertained,
Forever!