Can they be cleaned up? Yes. Is it economical? Probably not. But, in theory one could bring them up in a sealed box, then incinerate them on the ship. This would require literally building a ship for that one purpose with very specialized equipment and government supervision so not even a single shell walks off. IIRC France and Belgium have successfully disposed of equally corroded gas shells from Zone Rouge.
The first solar panels weren't economical either yet here we are. Going over the investment mountains is always slow and dangerous ,but the descent into the next valley might be close.
