Cloth may be salvaged by folding, and sewing two sides to form a bag about 20 cm X 10 cm.
Fill the bag with uncooked rice, and sew the bag shut.
Place in a microwave with a cup of water, and heat for 2-3 minutes.
One then has a heat bag which can be applied to aching backs and joints for 5 minutes.
Not predisposed to leaking, like the plastic blue gunk-filled bags that are sold in pharmacies.
Who knows, the OP could start a cottage industry in Thailand, if he has enough sexual interludes.