bag, valise, stuff, pad, surname
褚 centers on a container or covering made of cloth: a bag, valise, or padded garment. The surname sense is a separate application of the same character.
褚 combines 衤 (clothing) with 者, which likely contributes the sound. The character originally referred to a padded garment or cloth container.
The clothing radical 衤 beside 者 suggests something made of cloth: picture a padded bag or valise stuffed with soft fabric.
For チョ, imagine choosing a bag from a pile: choose -> チョ, and the bag is a 褚.