Full details for getting off the blacklist of @cheetah is available in @steemcleaners's discord server. You can join it by following link
https://discord.gg/8g65JY

As far as @appreciator's service is concerned, you just have to use it responsibly, as clear guidelines are mentioned in this post. If one has already made his way to blacklist then he can always amend his mistakes by publishing quality and genuine content, then after that contact me on discord or steem.chat