While Raw, the idea is nice, Although the skill would just be another Pain to get through ,like fletching.
We've already got Uber-Afk skills, Like Cooking, Fletching, Woodcutting..etc
No need for any more.
I think, rather than add it to cooking, fuse the two together.
Call the new skill, which incorporates everything in cooking, I don't know, something that'd work? I know there'd be a word out there.
but it'd add a whole new dynamic to the skill, and minigames could be developed around it. Good luck with this.
amending my last comment, i think it would just be tedious. I don't see the point, apart from the realism which i don't think a lot of players are interested in, considering other things in runescape.