Bourbon Barrel Explosions from Sulphur Wicks

I've heard that it's dangerous to use sulphur wicks in bourbon barrels, that it can cause explosions. I have one that aged Bourbon County so it hasn't had bourbon in it for awhile. I've also had a storage solution of cleaning soda and citric acid in it for a week or so, so it's been filled with water for awhile. Do people think it'd be safe to drain, dry, and use the wick?

It seems like all the alcohol in the wood would be dilute enough at this point.

LMK, thanks.

Why do you want to use a sulfur wick? Why not just use metabisulfite?