How can I properly clean big pieces of wood?

Hello everyone,

I recently bought a nice secondhand 45×45×60cm Exo Terra enclosure. It was a good deal and it came with some very nice and big pieces of spider wood and a cork background (not glued to the glass, yay!). I just had to clean it properly and replace the metal mesh at the top and it's basically perfect.

Now, I'd really like to use the wood and the cork background in a bioactive set-up, but I want to make sure they're safe for the gecko that will live in there. The seller used to house a crestie in this enclosure. I have no garden and I don't want to pour boiling water in my bathtub as it came with the house we recently bought, it's not ceramic (maybe acrylic?) and I don't want to risk damaging it. I was thinking to place the branches/cork panel in the kitchen sink, give them a good scrub with some soap, rinse and pour some hot (boiling) water on them, but I won't be able to fully submerge them. Do you think this can do? Any advice?