I think, and could be wrong here, that the +scavenge code referenced isn't a necessity to eat or find potable water.
The one's I've seen that were enjoyable were added as an RP booster. They might find interesting food (twinkies in the wrapper still) or other odds n ends, location dependent such that scavenging a house might turn up a first aid kit, but scavenging in the forest might find murshrooms or some old junk. Just it was never a scavenge or die implementation. Again, only from the times I've seen them and enjoyed them. But similar to the Cheese Hat, which is sort of what I was getting at in that scavenging on survival places is fun, they need updating such that the same odds and ends don't keep cropping up. On the place I used it most, plastic model (car or some such) cropped up, it was a novelty until everyone had one to build and couldn't find model glue. Its a simple fix too, instead of just generic list, fun unique things could be pulled from a word bank and removed as they're found.