Wood dowels

[Ectotherm1]

Quick question, I bought some wooden dowels at Wal-Mart to use in my cresties enclosure.
Would I need to seal them, or can I put them in the terrarium un-treated?
I know branches from outside need to be coated with something like Minwax polycoat, would I just do the same thing with the dowels?
I'm worried about them molding, as I had a piece of grapewood in the cage previously that had mold covering it after about a week.