You can replace the water in soap recipes with herbal tea, but most of the properties (color and fragrance) are lost. The best way to use herbs in soap is to add dry, finely powdered herbs to the fats before adding the lye/water. Use anywhere from 1 tablespoon to 1/4 cup dried herbs to 1 lb. soap. Coarsely ground herbs should be restricted to about 1 or 2 tablespoons per lb. soap because they contribute a coarseness to the soap that sometimes makes it uncomfortable during use. The nicest way to add properties of herbs to soap is the addition of pure essential oils. Most soap develops a "lye/fat" odor, which essential oil prevents. Use anywhere from 1 teaspoon to 2 tablespoons essential oil per lb. soap (depending on the strength of the oil). Color is an illusive thing as far as soap is concerned. Natural colors can be obtained by adding 2 tablespoons red clay, calendula petals, or palm oil (yellow).