Bestmixer got shut down because they were too explicit in how using their site may help its users break the law.
And bitblender didn't give people a week to withdraw their coins, they have people a day, and then several hours more, they have claimed they're wiping everything after that. IIRC, some users found that their funds were later moved to new addresses, indicating that bitblender didn't get rid of private keys associated with addresses to which people deposited their funds.
Ah well that's bad then. Thought they gave users a week which i thought was pretty fair. Guess there's no way to contact them too now.
Also i think most mixers now don't really mind where coins are from tbh.