Adding Brett C to a barrel of old ale?

I brewed up an old ale recently and after 4 weeks in primary stuck it in my 5.25 gallon whiskey barrel. I'm thinking of adding Brett C to get some of that stock ale taste and start inoculating the barrel for funkier things once all the whiskey character is out. Should I just drop a tube of brett into the barrel right away? Or wait a while? Is that too much brett? The beer will be in the barrel anywhere from 2-8 weeks depending on taste. The barrel is probably already getting some funky things since it is sitting in my unfinished garage near an old wood work table, but I thought I'd help it along.

A tube of brett isn't too much. Actually, the cell count in the brett packs/vials is much lower than ale & lager strains. You might as well toss it in right away. Brett C can be a bit of a slow-poke sometimes, so that'll give it more time to do its work.

The only time I would wait is until after primary fermentation is done, but you're already well beyond that point with this beer anyway. Good luck!