Created a group chat called snowball.thread on SimpleX chat. Messages delete after 30 seconds and you can delete your messages.

https://simplex.chat/contact#/?v=1-2&smp=smp%3A%2F%2FHWK6x65IcNpRyGDQUtOMSSofcQv2D72-NbEmqg-SwAE%3D%40smp.sethforprivacy.com%2FFn-g5JtzyFl7drpD8GsvW41JMMtBeQXs%23%2F%3Fv%3D1-2%26dh%3DMCowBQYDK2VuAyEA5Y1xkOdbJtNC-h-4u3-lt1uWYjNWhkFN_zQtEb0bVWs%253D&data=%7B%22type%22%3A%22group%22%2C%22groupLinkId%22%3A%22Vh7eoJHC284S1UdAP3rATg%3D%3D%22%7D