I have in the past stored things, and I think a doll for storing emotions may be a good way to really get to know one's self, but, ultimately, I think our experiences and their associated lessons are stored within us. As long as the lesson is understood then I think that information is already available in memory, including past understandings from those who have gone on before us if one has access to "collective memory". If I need to do a working for something for which I need anger, then chances are I am already angry. Personally, I don't like to do things in an emotional state, but the feeling should be there already. I do think if one has something they need to explore, and it is too close to home or too painful to be objective, then the psychological act of "storing" the memory for objective exploration could be helpful (this is much like how I will write a story about a character who is dealing with something that I am going through but I am not objective enough to be able to deal with it in a non-reactional state, so I have the characters deal with it, which removes my emotions from the situation and gives me a clearer head).
I have a piece of willow that I talk to about very emotional issues, and just the talking through it often helps, and she also houses a spirit that is very helpful in guidance. Not in fixing or making it all go away, for that is not her nature, but in helping me to know and remember that I'm not the only one to ever experience xyz and that others before me have gone through this and survived, and overcome, etc., and how they did it. This piece of wood I have, incidentally, enclosed in a doll. It makes it easier to carry in mundane places. She is not huge and it's easy to hang her from a paperclip by my desk if I feel the need for her guidance and/or company. But her heart and soul and memory is not specifically mine, her heart is willow and her memory is of those who have ever called upon the willow for guidance.