Muggles' Guide to Harry Potter/Magic/Peskipiksi Pesternomi

Overview
Peskipiksi Pesternomi is not a real spell.

Extended Description
This spell appears to be Gilderoy Lockhart's attempt at a spell to disperse the Cornish Pixies he released in one of his Defence Against the Dark Arts classes, but it didn't work, and it might even have further irritated the pixies in question. The immediate result seems to have been that one of the pixies grabbed Lockhart's wand and threw it out the window.

Analysis
The spell incantation seems to be based on the English phrase "Pesky pixie, pester no me". As most real spells seem to have incantations that derive from Latin words, the fact that this one is based on an English phrase makes it immediately suspect.

Given the nature of his actual magical expertise, which we discover late in the books, it is uncertain whether Lockhart had ever really tried to use this spell. Equally, it is uncertain whether he created this spell himself, or was given it by someone who didn't completely trust him. We see throughout the book that the teachers at Hogwarts seem to have a very low opinion of Lockhart's magical skill.

The purpose of this spell seems to be purely to point up Lockhart's incompetence.

Questions

 * 1) What is the effect of this spell?