Mike, you should use the penetrating sealer first, otherwise the first coat will block it from penetrating the wood.
Some technical info: Wood had molecular sites in the cellulose matrix that attract water molecules. When you dry wood below about 25%, you start pulling those water molecules out. When they leave, it's possible for some of the molecular sites to bond to something else, so water can't come back to that spot. The more times the wood gets dried, the less water it can take back up, and the more stable it becomes. When I manufactured arrow shafts, I developed a dehumidification kiln cycle with low heat that dried the wood to about 10%, then raised the moisture level back up, then redried a little drier, through several cycles, with a final moisture content target of 6%. I believe it made the shafts more stable in use, and less likely to absorb much atmospheric water. The cycle had the added benefit of stress-relieving the wood while working it through these hysteresis cycles.
That's how getting the ash drier makes it more stable, too.