You may be lucky, depending on how cleanly the wood is cut and who checks it. It may be considered a finished product and slip through. I have seen carvings come in withought treatment, and have collected carvings that came through but the owner later found frass (bug crap and sawdust) being pushed out from multiple small holes in the wood. Interestingly, if it sneaks in and later looks to be contaminated, treatment is at Government expense, if you report the problem. Quarantine collects, kills and returns. Timber can be treated with Methyl Bromide fumigation or radiation, but both cost. Importing just the one item is hard, comercial operators sometimes have an option of treating with Methyl Bromide offshore, which is usualy cheaper. Paperwork is the key, as quarantine departments are just another part of the public service, and thrive on paper. Hope you get lucky. They may not even look.