The difference being in Ireland the land was transferred from catholic to protestant lord creating religious division. In this case you would be breaking up the plantations and parceling the land out to homesteaders. In a generation or two much of that land will have been sold and resold. Its no longer a political issue it becomes economic issue, and the amount of sympathy for exslaveholders is probably not that high.
But what has this to do with reducing nostalgia for the Confederacy?
More nonslaveholders fought for it than slaveholders, and many nonslaveholders were related to slaveholders - so picking on former slaveholders has no particular effect on the way the CS is remembered.
If you want to do that, the only way is to "short circuit" things by having the CSA collapse in the first year or so of the war. That way, a large part of the Southern white population probably never fight for it, or get their homes burned down by Yankees, or anything else to create a strong emotional bond with it. So it is far easier to get a South in which the CSA is seen as a big blunder which should never have been undertaken. This is particularly possible if Lee and Jackson have never emerged as leading figures, to become idolised "legends in grey". That leaves far less to romanticise.
Also, of course, a shortened ACW likely means no Radical Reconstruction, so that the South is brought back into a Union not much different from the one it has briefly left. Combined with the far smaller casualty list from this shorter war, the reunion is far less painful for the South, and there is that much less to regret about the failure of the abortive rebellion.
It's not guaranteed to work, but it certainly stands a better chance of success than any crack-brained (and almost certainly ASB) schemes of large scale confiscation etc, which would serve only to unite Southern Whites in hostility to the government - and in even greater reverence for their Confederate heritage.