I definitely agree with Bling.
If you can, take the fast till natural hunger returns.
That way, you are assured that the most work will get done on the cyst. It should be well worth it.
It seems that the body goes through different layers of work on the body during a fast.
If taken all the way, you will be assured the most action on the cyst at what ever point the body gets into the most intense work on it.