Re: reusing ccd hive boxes....
It all depends what caused the "CCD".
If the combs have not been eaten by wax moths you could check for signs of AFB. If no AFB then reuse the gear.
There are other things such as certain poisons that could leave contaminants but not practical to check for all of that plus it will not really be contagious, go ahead & use the gear.
Most of these cases with small part timers the cause was starvation, mites, or something of that nature which means the gear can be reused.
44 years, been commercial, outfits up to 4000 hives, now 120 hives and 200 nucs as a hobby, selling bees. T (mostly).