Dash was only briefly used on Nucleus (which was, like Dash, a scam).
Now we keep hearing unsubstantiated rumors that other DNMs are using Dash, but we don't see any verifiable information and Team Dash's Official Position is that they rebranded from Darkcoin to avoid the association with Dark stuff.
However, the only DNM besides Nucleus using Dash that's been reported by the media is a nasty child abuse ring.