Wanted to check in with you guys about shaking or rocking the fermenter. Is there any harm in doing it? I have a tilt hydrometer. At times it reads off by a big amount. This I think Its due to krausen or other crap, stuck to the top of it. By shaking, I can rinse or splash the crap off it. Is this harmful in anyway throughout the process? No air is introduced during the shaking.