Cleaning charms, right... Derry had thought she was quite good at those, she knew scourgify, and now she knew vacavus... but people had said these already. She brushed a bit of dust out of the way and put her parchment down, scribbling her name at the top and starting to take notes. Oh! "Would the Skurge charm work..? For other things than ectoplasm I mean..." No harm in wondering, right?