I had a cauldron that I couldn't stir without gassing ourselves as Narcissa was dueling with kid gloves, merely trying to push them back. "Use Bombarda! That might actually stop them!" Thinking quickly, I pushed a stirring rod past the charm and into the cauldron, using my wand to levitate and stir the potion remotely. It took more effort than if I did it manually, but this way was safer.