Some messages are meant to be seen or heard only once.
Voice message played once
When you send a voice message, you can choose to have it played only once. After the other person listens to it, the file is deleted from the server. In a group, each member can play it once, and the file is deleted after everyone has played it. The sender can replay it as long as it exists.
Free, you can send a few a day; with Puls+, as many as you like. In your privacy settings you can make voice messages go out this way by default.
Scratch message
It sits under a silver layer, gets scratched with a finger, is read once and disappears. See chat gestures.
What you cannot do with them
- They cannot be marked Keep and cannot be kept with Puls+.
- They cannot be saved to Moments.
An honest note
Nothing stops someone from photographing the screen with another phone. And if a voice message played once is reported for harassment, its file can be held for moderation instead of being deleted. An end-to-end encrypted voice message stays encrypted in the held copy too, so we cannot listen to it. See Blocking and reporting.