This "parenting website" seems to follow the principles of Re-evaluation/Co-counseling (RC). Patty Wipfler was (is?) the International Liberation Reference Person for Parents.
In an article written for RC mag, Present Time (issue 91), Patty writes about seeking out isolated and vulnerable communities and providing them with child care assistance. RC principles are introduced but not identified (I prefer full disclosure on such matters).
RC is referenced in one H&H source-BEU book intro/acknowledgement in one sentence--after purchase & easy to miss.
RC seems to believe in "liberating" people from their "oppression" (such as ones' sexuality, Catholicism, Judaism, etc.).
The "tools" of H&H seem to mirror RC. Although initially helpful to a tired and stressed parent, they are quite limiting and lack comprehensive integration of evidence-based parenting theory.
You can also purchase Patty's booklets and videos on RC's publications website: https://rationalisland.com
By the way, not sure if everyone knows this, but you're encouraged to say things you would never say to anyone else, during on-line classes. You are being recorded but there is no explanation for the purpose of the recording and I was NOT fully informed in advance.
Proceed with caution!