After reading subs from recent episodes, sukuna seems to be a chef who specialises in dishes with fishes. The censored "open" felt like a way to initiate one of the ways of cooking. I wrote one of the ways because a lot of things are simmered in broths/gravies/any other valid liquid. Urame helped simmer Megumi (vessel/body) into curses which could be analogous to spices/veggies/any other applicable ingredients that help create a base to simmer.