http://btcmixer2e3pkn64eb5m65un5nypat4mje27er4ymltzshkmujmxlmyd.onion/help/faq
If the Mixer does other stuff behind the scenes, for instance
sending your money to a Bitcoin Exchange to get alternative Coins
back out, or converting to and from another crypto-currency. That's all
cool, whilst the exchange doesn't freeze their account mid-mix,
asking for "proof of funds" or
the external service they rely on isn't exit scamming or has stopped
working for whatever reason.