We use stakes made mostly from Oak and we don't have any problems with them. A buddy of mine has put out numerious stake beds that are nailed together and they have been out for several years with no problems. A few of his sets are in open water where there is a lot of boat traffic and waves and they are still holding up well. How I know this is the water level is low enough now and they are sticking up. We fished them the other day while they were sticking up and we caught several fish off of them. They are water logged and nasty lookin but they are still there and holding fish so I guess that is all that matters.
If you make bucket stake beds out of them, I would think they would last even longer. I just think it takes that kind of wood a long, long time to rot under water. Like a stump in the lake, there are stumps in the lake I fish that have been there since the lake was built about 40 years ago and are still there and hard as rocks.
My thoughts on this matter.
CX.