This leads into something I considered earlier -- short cuts don't work, e.g., 9 women cannot make 1 baby in 1 month.
Straight bourbon must be aged at least 2 years in new oak barrels, while bottled-in-bond must be aged at least 4 years. Bourbon barrels cannot be re-used for bourbon; from what I've read, most are resold to Scotland, which has no requirement.
Soaking cubes for a few weeks, or even months, will not produce the same effect. Upon reflection, it's necessary to buy used bourbon barrel parts or soak cubes for a couple of years.
Or add bourbon to a wine to change the flavor.