i would advise against allowing the new colony to clean out the dead brood, although i have seen it reported here that folks have done it with no ill effects.
i am not recommending this, and i am now rethinking my ways, but here is what i have done in the past:
use a garden hose with an old fashioned spray nozzle and/or compressed air to uncap, dislodge, and blow out the dead brood
wash the entire frame of comb with the garden hose, shake out the water, allow to dry well
use a spray bottle to mist 3% bleach on the frame, allow to set for a while, then shake out excess bleach, allow to dry well
i am not recommending this, and i am now rethinking my ways, but here is what i have done in the past:
use a garden hose with an old fashioned spray nozzle and/or compressed air to uncap, dislodge, and blow out the dead brood
wash the entire frame of comb with the garden hose, shake out the water, allow to dry well
use a spray bottle to mist 3% bleach on the frame, allow to set for a while, then shake out excess bleach, allow to dry well