According to Ashley's post in HTML5 game dev forums about CocoonJS dispose(); is useless:
[quote:31d1zbe9]When we talk about "memory management" we only mean lazy-loading image texture memory, which you say you've already got covered. We added support for lazy loading in Ejecta with some help from Dominic, and all existing browser engines already do that. CocoonJS's dispose() function is useless because by the time you call it it's too late - it already loaded the image data in to memory, it doesn't help stop that up-front cost.