"다 안나오지만 수세미를 우려먹는다고요? 사실인가요. 우려먹을 수있는건가요?"
- 다 안 나오지만 => not all of it is coming out / can't see/get all of it (context-dependent)
- 수세미를 우려 먹는다고요? => you mean you cook/steep 수세미?
- 사실인가요? => Is that true?
- 우려 먹을 수 있는 건가요? => Is it something that can be cooked?
=> I can't get the whole thing, but are you saying you cook the scrub pad? Is that true? Can it be cooked?
수세미 is the scrubber pad. In the old times, it was made from plant stalks.
Every household had it to clean pots and bowls, but no one would have ever thought of cooking it - it's unthinkable.
So the line can only make sense coming from a naive child, probably in a children's fairy tale.