According to the (non peer reviewed) scientific experiment found here, simply placing a piece of kiwi onto gelatin that has set will cause the gelatin to be hydrolysed by actinidain.
> This experiment aims to show the effects of Proteolytic enzymes on proteins and, subsequently, the effects of extreme temperatures on the proteins themselves. Petri dishes filled with gelatin, a derivative of collagen, were acted upon by kiwifruit samples overnight. Some samples were fresh and used as controls; others had been frozen or boiled for two, four, six, eight or ten minutes. The mass of digested gelatin was taken the next day. The results ultimately reflect the effectiveness of the actinidin, the kiwi’s Proteolytic enzyme, under normal conditions and after exposure to extreme temperatures.