Dawn dishsoap and hot water in an empty Kirkland cashew container, shake and swirl around, triple rinse with clean water. Then toss in the Iosso case cleaner kit for a couple minutes, triple rinse with clean water, and then air dry; I usually bunch a few cases in hand and flick the water out to speed up dry time.
Have never owned a tumbler.
Chris
Cashew media? Fascinating...