"Really, it changed?" Fred and George shouted in unison. "How did you even notice? What were you thinking about that made the Scouring Charm different?"
"I can't really explain it..." Filch furrowed his brow and thought carefully. "It was just watching those House-elves clean... Every time, I kept thinking... shouldn't the Scouring Charm have some bubbles too?"
"When professors punished students with detention, I saw those students use the Scouring Charm. Their Scouring Charms... I remember they produced bubbles too..."
"That's right! Those bubbles would stick to the armor, and every time their detention ended, I had to clean it all over again. It was bloody annoying!"
"Wait!" He seemed to think of something and immediately widened his eyes at Fred and George, demanding viciously, "Was this one of your rotten ideas? Is that why the Scouring Charm turned out like this?"
"Oh?" Fred grinned as he raised both hands in a surrendering gesture. "You caught on pretty quickly. You immediately thought we were up to something..."
"This Mr. Filch..." George raised a hand and pointed at Wizet. "It seems he really trusts Mr. Lovegood! Even though the Fake Wand was designed by Mr. Lovegood..."
"How could that possibly be the same?" Filch said without reservation. "Don't think I don't know... just how many bad things you two have done!"
Fred shrugged. "We haven't even blown up a toilet. How many bad things could we have done?"
"Or..." George raised an eyebrow at Filch. "The next time we blow up a toilet, we can let you know so you can come watch? Then you'll know exactly how many bad things we've done!"
Wizet said, "The final effect of the Scouring Charm is the same as its incantation, 'Scourgify'—it makes an object clean. However, there's a tip mentioned in The Standard