I was cackling and clapping while I read this. I DO LOVE IT when Ginny goes off on someone, even when it's Harry! It's so much more fun than for her to be all sad about his breaking up with her and not being able to help him.
I also loved Hermione & Ginny calling the boys idiots and "the Dynamic Duo" and all that. A grumpy Hermione plays really well off a bad-tempered Ginny. Also, you wrote the instructions and box for the WWW WooDoo Doll in such a clever, humorous manner, just as one would expect WWW product packaging to read.
My only question: do you really think that Harry is so secure in his physical appearance that he would stand in the kitchen in front of the other three in only his knickers, and THEN run outside after Ginny without having put on the pants he was carrying? (I can understand being caught up in the fear of billywigs' stings for a moment. But, once he realized Ginny's WooDoo Doll was the culprit, shouldn't he have blushed and been a bit embarassed to be practically naked in front of the girls (despite his anger at Ginny's physically torturing him)? Also, Ron didn't seem bothered by having to check over ALL OF Harry over for stings. Knowing them, wouldn't he have given Harry at least A LITTLE good-natured teasing about not liking him THAT WAY, and Harry would owe him for Ron having to look him over so thoroughly? Maybe not, but it just seemed too easy for Harry to not get any teasing about that.
Please keep writing. It would be a shame for someone who writes funny stuff the way you do to not keep doing so. : )