The 51-year-old actress embarked on a three-day trip to India with her spiritual guru Hargopal Kaur Khalsa last week amid reports she and estranged spouse Ashton Kutcher have finally filed divorce papers.
A source said: "Demi says she's now at peace with the divorce, but she felt she needed to clear her head of any negative energy.
"Demi now insists she is fully cleansed of Ashton and is even ready to welcome Mila into her life."
The 'Margin Call' actress undertook the trip on the recommendation of her friend Russell Brand, who embarked on a similar retreat following the end of his marriage to Katy Perry.
The source said: "Russell said it would help her gain perspective and keep her on track."
However, the trip wasn't easy for Demi - who endured a stint in rehab following her split from Ashton - as it involved being totally silent, and she also attended 'Craving, Desire, and Addiction', a conference hosted by His Holiness the Dalai Lama.
A source told Grazia magazine said: "It was tough for her. While she's comfortable being alone, it was incredibly challenging not being able to interact.
"Demi continues to seek help for her long-term battle with drug and alcohol addiction and after she split from Ashton she fell back into an addictive trap. She's conscious of not letting the divorce send her back into a dark place."