I have had this as part of an overall approach.
I was very self critical, extremely avoidant of emotions and other people, felt constantly unsafe and was continuously attacking myself, and it was causing suicidal thoughts when I was triggered into shame or anger.
It was used to prepare me for EMDR as I have have major issues feeling safe, trust issues with myself and my therapist.
I never learnt how to self sooth as a child, so I have had to learn how to care for myself, something that most children in stable homes naturally learn from their parents. My mother hated me, and then I took over that role and hated myself even more than her.
It has taught me how to calm and stablize myself, to be caring and campassionate towards myself, and to quiten my inner critic when I am triggered, I no longer abandon myself due to the rage I turn inwards instead of at my abusers.
It is not self pity, it is self acceptance, treating myself like I would a friend.
It helped make a massive difference to my life, I am no longer depressed, and rarely have suicidal thoughts, and if I do they come, I care for myself and they go. It hasn't cured me, but it has stablized me and taught me to regulate my moods.