Ancestral healing is a hypnotic process that resets/rewires the ancestral programs we "inherited" from our parents to assure our safety/survival.

For example, we cannot feel our feelings, because our parent(s) were strict and/or cold with us. The program (i.e. the coping mechanism) we inherited in this case is probably "showing feelings is dangerous" ("if I show my feelings dad will be angry with me/won't love me/will reject me/I will die"). A survival instinct.
"Inherited", because most likely our dad was treated the same way by his dad. And his dad by his dad, and so on.

"OK," you may say, "this was in childhood, a long time ago - why can't I feel my feelings now? Why can't I show up authentically for myself and for my partner?"

The thing is, that program is still actively running in our subconscious, because our psyche is wired to keep us safe. Knowing on the conscious level that's it's safe to feel the feelings does not turn off the subconscious program, because it's a "different level of clearance". We have to go back to the source - to subconscious - turn off that program, and activate a new program of "love and compassion".

This is what ancestral healing does - it turns off the "negative" coping mechanism/program and activates the love and compassion. It heals the entire ancestral line on either dad or mom side (during one process we can do either or). After one week the process can be done for the other parent for best results.