“I had no memory for incantations and my potions were a family joke! Now, after a Kwikspell course, I am the center of attention at parties and friends beg for the recipe of my Scintillation Solution!”
-- Madam Z. Nettles of Topsham in Filch's Kwikspell Course Brochure (CS8)
Madam Z. Nettles was a witch from Topsham, England, who used Kwikspell in order to improve her magical abilities.
Nettles claimed to have struggled with potion-making and remembering spells before taking a Kwikspell course. On Kwikspell promotional literature, Nettles attributed a rise in her popularity to the course (CS8).
Nettles's poor potioneering skills were notorious among her family (CS8).
Other canon notes and references
Her testimony was part of the Kwikspell literature that Harry once read in Filch’s office (CS8).