So here's the problem:
This barrel leaked so bad, I couldn't fill it up enough to swell the staves. Was about to give up on it when a friend had a brilliant idea.
We wrapped the barrel in several layers of shrink wrap, the same stuff used to wrap pallets on a loading dock. We then put the barrel in a kiddy pool to contain the water. The shrink wrap allowed us to fill the barrel and help hold moisture against the wooden staves to help swell the wood. The kiddy pool allowed the heads to be partially submerged and stay wet.
The barrel still leaked, but the leak was slowed enough so that we could keep filling the barrel. After we filled it each time, we bunged it and rolled it around in the kiddy pool. Several hours later, most of the leaking stopped.
Voila.

This barrel leaked so bad, I couldn't fill it up enough to swell the staves. Was about to give up on it when a friend had a brilliant idea.
We wrapped the barrel in several layers of shrink wrap, the same stuff used to wrap pallets on a loading dock. We then put the barrel in a kiddy pool to contain the water. The shrink wrap allowed us to fill the barrel and help hold moisture against the wooden staves to help swell the wood. The kiddy pool allowed the heads to be partially submerged and stay wet.

The barrel still leaked, but the leak was slowed enough so that we could keep filling the barrel. After we filled it each time, we bunged it and rolled it around in the kiddy pool. Several hours later, most of the leaking stopped.
Voila.