Although this trick is commonly called “The Chinese Rice Bowls”, it is believed to have originated in India, not China. In Die Zauberwelt, Vol. 7 No. 2, Feb. 1901, p. 25), Carl Willmann describes a set of bowls fashioned after the Indian style, with one of the bowls having double walls to form a water reservoir. Willmann introduces the article with this: “[The bowls] are manufactured by the author exactly like the original, the authentic Indian vases.” His wording may allow for some ambiguity, as it is not clear if the double-walled method was used in India, or simply that Willmann had imitated the shape and style of Indian bowls. However, lacking evidence to the contrary, the doubled-walled method was likely that used by Indian conjurers, and that is how Prof. Hoffmann interpreted Willmann's description when loosely “quoting” it in Later Magic (1903, p. 557). The double-walled method eventually became known as the Brahman Rice Bowls, so-named by the Mysto Company (see The Linking Ring, Vol. 49 No. 3, Mar. 1969, p. 24).
Frank Ducrot is the inventor of the now commonly used method employing a clear disk. He published his version in Mahatma, Vol. 4 No. 9, Mar. 1901, p. 454. Ducrot says in his write-up that the basic trick already existed and is “ever popular.”
In 1933, Al Baker came up with the method using a rubber cover in his marketed “Chinese Rice Bowls”; see The Linking Ring, Vol. 13 No. 2, Apr. 1933, inside front cover. The instruction sheet for the trick is reproduced in Todd Karr's The Secret Ways of Al Baker, 2003, p. 573.