Tea pillows have long been used throughout the orient for their aromatherapy (and antimicrobial) benefits. The fragrance of tea is held to be calming, and they are used in a manner similar to the way you use a lavender pillow. The fragrance of tea can sometimes become faint over time. If you can't smell your tea pillow, try placing it in the sun before use, or placing it on a gentle heat source, like a heating pad. If that still doesn't work, pick open the seam and fill your pillow with fresh tea.
Thailand -- Small silk or brocade tea pillows are one of the most popular Thai souvenirs. They are often made using fabrics that were handcrafted locally, thus providing both the cloth makers and the tea producers a measure of self-sufficiency.
Japan -- A company called Corma (in cooperation with Itoen Tea Company) has developed a way to recycle used tea leaves into resin-based beads for pillow fillings. These are said to feel similar to buckwheat pillows, but with odor eliminating properties and no potential for weevils.
China -- Tea pillows have been considered medicinal in China for thousands of years. They would sometimes be mixed with herbs designed to treat a specific condition, or to enhance longevity. They are also considered a natural sleep aid. They are available today in a wide variety of sizes and fabrics.
The pillows can be filled with any high quality tea (typically green or oolong), or with a tea that has an added fragrance, such as a jasmine tea or a chai. I have been using tea as a fragrance element in my herbal sachets for years. Now, I've designed a Kimono shaped pillow which will be available in Fragrant Green (gold fabric) and Chai Spice (red fabric).