Ha, I thought it was just us blue-haired oldies who remembered *plonk*. I'm only using it in my admin notes, and only in public if I'm sarcastiposting about the week's moderation adventures from a mod-persona account.
Generally NOT in interpersonal chat ... I stick with the "move on" part if I need to block and move on.
I'm also trying to take a breath and note if a "mute" is more appropriate, as those can be time-limited.