Have you gone mad?
In book 1, Ron reminded Hermione that she was a witch and therefore could use magic to save them from the devils snare. What if they relied on magic in other situations too?
In Chapter 31 of the Deathly Hallows, Crabbe set fire to the Room of Requirement. Harry unsuccessfully tried to extinguish it using aguamenti.
Quote from the Deathly Hallows: "Malfoy grabbed the Stunned Goyle and dragged him along; Crabbe outstripped all of them, now looking terrified; Harry, Ron and Hermione pelted along in his wake and the fire pursued them" Harry coughed, suddenly afraid that he was going to die from all the smoke that invaded his lungs, when all of sudden an idea entered his mind: Dobby told him the room was always equipped with what the one who had entered it first desired. He had entered first, had he not? With all his remaining willpower he imagined the room conveying a means for extinguishing the fire, for saving him and his friends. But nothing happened. He scrambled forward, always trying to remain one step ahead of the fire, looking out for Ron and Hermione as well. He once again wished for the room to help him survive. In his desperation, he closed his eyes and concentrated only on wiping out the fire before it could wipe him out. The air around him grew incredibly hot, but the next moment, he felt like being in an oversized freezer. Had it worked? He opened his eyes, only to be rewarded with a cold breeze directly into his eyes. He felt elated and concentrated on the room being not to warm and not to cold. When everybody stopped freezing, they looked around and saw that the diadem was charred black and had broken in two. Malfoy lunged at Harry, but was intercepted by a Stunner from Hermione, while Harry Stunned Crabbe. Hermione, with her considerable intellect, was able to deduce that the fire must have destroyed the Horcrux. Harry whooped in joy upon realising that they had come one step closer in killing Voldemort.