Whatsapp on iOS, how to delete voice messages?

Solution 1:

Now, after 1000 views on this question it's worth updating my answer:

Recently, a function has been added to Whatsapp that lets you delete ALL voice messages from a chat.

  • open Whatsapp
  • hit "Settings"
  • click "Data and Storage Usage"
  • click "Storage Usage"
  • select a chat
  • click "Manage..."
  • remove every checkmark except for "Voice Messages"

(You can also delete other stuff in there but I wanna keep all of that haha)