Local dm message deletion

So basically a feature where you can delete other people's messages in dms but only for you. There's some people who like to send me inappropriate stuff, and I don't want to see it. Sometimes I just come across old dms, click it, and I see that. And some people may think I'm looking at it on purpose, but it's because my friend or a random person sends it to me. And to add make it where it takes a day or 2 to delete just to make sure you didn't accidently click it.