A Plan to Annoy Filch
First you have to gather six people. Say they are Minerva, Sirius, James, Lily , Peter, and Remus.
Then you have to make yourselves look identical. That is essential. Not even eye color can be different.
Then make a map of strategic points like this to set dungbombs on. You must have six dungbombs.
Filch's office SJ║ LM ║ PR║
LM ║ PR ║
The people are in pairs, labeled by their first initials. Each pair will have two dungbombs.
The first pair, SJ, will set off a dungbomb right by Filch's office. The noise and smell will attract Filch and S and J will dance around and confuse Filch before running to their next location. Then LM will set off a bomb and so on and so forth. SJ should have three bombs and when their second turn is done they will run back to Filch's office.