I know some people play mimic on jealousy and struggle. So this message is to help with rin's part (aka rat devouring). If your getting chased by her and you have a rat, look around for rooms with ropes, or find your way to spawn, the garden, or to the room with the book. It turns out that shimenawa is actually a sturdy rope, and rooms with that so-what-called rope will prevent rin from going in the room. The dolls won't protect you at all, except for the dolls in the book room because of the rope.