A direct pitch on top would work great. I've done it twice and one was my RIS (1.105), the other being a big Tripel. I've also done the wash thing for brews below 1.070.
I would try and rack off as much of the Irish red as possible, but I doubt you would get much flavor transfer to a big stout like you're planning.
Primary #1: Big 50 Barleywine #2:Empty
Secondary #1: Peach Rhubarb Wine #2: Empty #3: Empty #4: Framboise Lambic
Kegged: Pumpkin Ale, Orange EPA, Piker Liker Porter
Bottles: Red Rye IPA, Dark Belgian Strong, Belgian Golden Strong, Kicked by a Moose Scotch Ale, Apfelwein, Russian Imperial Stout, Carmelite Tripel, Rhubarb Wine, Barolo Wine
On Deck: Umlaut my Kölsch V