It appears that they are just infusing, through vacuum pressure, the chemical 'in through the out door' in as much as stomatae are the plants' transpiratory system. The four hour limit, I theorize, is how long this process takes to kill the organism. Getting bio-luminescence genetically is a more 'laborious' process, but once it's developed, theoretically, the luminescence would last more closely to the length of the organism's natural life.