Flesh and Stone reduces the self damage from forbidden rite Ref: 387 718 715

If flesh and stone is in sand stance you will take less damage from forbidden rite.

Tested by having 58% chaos res which should result in a savage hit. But when flesh and stone is enabled forbidden rite no longer savage hits you.

As flesh and stone states that enemies in aura radius should deal less damage I don't think that self damage should be included in that.

Tested this again now, it's still bugged.