Able to remove completely Dm's and other past conversations from other users for convenience

A feature like this is what Facebook already has for example, to delete a conversation completely from messages they can be deleted as the entire conversation/dm's second extra feature that user related for extra feature is to clear past conversations from other people were maybe not added as friends but the conversations get left there and possibly they can be easily remove for convenience. Or can be removed individually, For specific dm's. And the second feature/option was that you can search for past conversations with other people and delete the ones you don't need since once there there they stay in the past conversations from the ''find or start a conversation'' which you can see from users that other users have talked/messaged these two features would come in handy.