"have you (or they) ever tried to wash the carbon into or out of organic matter using water?"
You're missing the point. It's not about washing out, it's about burial. The flood buried massive amounts of organic material, which took it out of the biosphere. This is where we get coal, fossils, and all the other stuff in the geologic column.
As I mentioned, the amount of atmospheric C14 remained relatively constant between before-the-flood and after-the-flood. It is the amount of carbon in the biosphere which decreased so dramatically, thus making the C14 generated in the atmosphere more prevalent percentage-wise.
you really didn't read my reply, did you?
read it again.
read it carefully.
the "amount of carbon in the biosphere" is irrelevant. It is the amount of carbon-dioxide in the atmosphere which pertains.
read it again.
read it carefully.
shoot for comprehension this time.