I tried this method. I put one ripe avocado on the shelf in the frig like I normally do and a few in water in the frig. The one on the shelf got eaten before it could be used as a control. The last one in the water sat there for about 3 weeks before I ate it, and it was in good shape. Much better shape than that control one would have been had we not eaten it so soon. There were a few tiny brown spots but all the avocado’s in that bunch had those even when first ripe. They were not the best advocados to begin with having some of those stringy fibers that they sometimes get. I plan to try again and hide my control better next time I buy a bag at costco.
I also wrapped a half eaten one in a paper towel. It worked almost as well as my usual method of squeezing lemon juice and wrapping in plastic wrap. If keeping for longer than a day, you will have to keep the towel moist. I am guessing it would have worked just as well as plastic wrap had I also used some lemon juice. One could moisten the towel with just lemon juice if you had an excess of lemons.
