I assume that a combination of high temperature and irradiation should be effective. Wood should not be damaged by temperatures high enough to kill living cell

I assume that a combination of high temperature and irradiation should be effective. Wood should not be damaged by temperatures high enough to kill living cells and it provides negligible shielding for radiation. However, after sterilization it may require more care than metal, glass or plastic, to avoid any later contamination. Presumably all the assembly must be done in a sterile environment. Unlike metal or glass, which could be washed in oxidizing acids to remove organic substances, sterilized wood may contain dead bacterial cells in its pores. For satellites expected to burn on reentry that would not matter. For exploring other planets, that would be undesirable, as this could provide false positives for detectors of organic substances.