interesting recipe. here's a (non-slowcooker) hot and sour soup recipe. it's very good.

hot and sour chicken soup, serves 4

3 cups chicken broth
1/2 cup water
1/4 lb small mushrooms
1/2 cup canned, sliced bamboo
fresh ginger, unpeeled- 3 slices about 1/4"thick
2 cloves garlic, minced
2 tsp low sodium soy sauce
1/4 tsp hot pepper flakes
1 lb skinless, boneless chicken breast
1 tbsp sesame oil
2 scallions
1/4 cup cilantro, chopped
3 tbsp red wine vinegar or cider vinegar
2 tbsp cornstarch
1 egg

in a medium covered saucepan, bring broth, water, mushrooms, bamboo, ginger, garlic, soy sauce and pepper flakes to a boil over med-high heat. reduce heat to low, cover and simmer while you prepare remaining ingredients.

cut chicken into 1/4" slices. in a bowl toss the chicken with sesame oil.

finely chop scallions and cilantro. in a small bowl, blend vinegar and cornstarch together. in another small bowl lightly beat egg.

increase heat of broth to med-high and return to a boil. add chicken to soup. stirring constantly, slowly pour in egg. stir in vinegar mixture. cook, stirring occassionally, until chicken is cooked through and soup is slightly thickenend, about 3mins.

remove ginger slices before serving and stir in scallion and cilantro.

and here's another. i know you're a fan of mr.bam.
http://www.foodnetwork.com/recipes/emeril-lagasse/classic-hot-and-sour-soup-recipe/index.html