I was cleaning a couple of my cups today, using a dilute TTO solution (3 drops TTO in just over a pint of water). Each cup was in the solution for several seconds -- just long enough to give it a good dunking -- and then rinsed thoroughly with tap water.
I know there have been some concerns with TTO cleaning, but what I've read suggests that dilute TTO for short amounts of time are pretty safe.
I've done it before with my Lilac Cup, and once again she pulled through like a champ. However, my tiny black Meluna seems to be... disintegrating? If I rub my hand along my Meluna, parts of the Meluna now rub off in little rolls -- like if you rub an eraser on paper to erase something, and parts of the eraser rub off.
I do realize this method isn't on the manufacturer's recommendations for cleaning the cup. However, checking this part of the Meluna FAQ suggests that oils should be okay with Meluna. And this was a very short exposure to a very small amount of oil (though I recognize that TTO is not your "average" oil).
I'm willing to own up to this as an unsmart move on my part. And I will be replacing my Meluna. (Tiny cup + ring stem = ROCKS MY WORLD by the time I finally get to period light days.) But I'm just curious, has anyone else had tea tree oil start to "eat through" their cup? If so, which cup? How much tea tree oil? And for how long had you been using the TTO?