I usually have a spare tank seemingly at the moment. Currently I'm using my hospital tank to soak some bogwood. If your tank isn't set up yet you could just use that, if not, give it a very good rinse with cold water and boiling to kill off anything. Then put it in your tank and be prepared for plenty of water changes over the next few months while it leeches out the tanins.
You could also consider getting a cheap plastic dustbin or something, or if thats too large, maybe some sort of stackable storage crate?
When soaking though, its worth de-chlorinating your water, or leave the water standing for a good 24hours or so to let the chlorine naturally disperse.