The first whiskey in the barrel was Blue Corn Whiskey from Balcones. I "re-whiskeyed" after draining out the Wheat Wine by giving it a rinse with hot water (fill up once, then drain and let sit hole side down for a day) then putting a 5th of Jack Daniels in it and swirling aound.
I have since "rumed" the barrel by repeating the above process with a 5th if dark rum. It now has my Imperial Pumpkin beer (aka Rumpkin) aging in it.