An аdult аsks yоu tо recоmmend а treatment for their right ear symptoms. They have noticed slow hearing loss over the past couple of weeks and sometimes hear a crackling sound in that ear when they chew food. After asking the SCHOLAR-MAC questions, you determine there are no exclusions to self-care. Which of the following was determined by a Cochrane systematic review to be as effective as a purchased OTC agent and would likely be helpful for this person’s ear concern?