Foolycooly said:
Can you find when the first one was and the last one (when its all over) and then delete all comments between that time frame using a script, yeah there may be collateral but it saves the mods a massive headache
Also for future maybe give mods the ability to lock all comments for a while
Don't have massive experience running a website so I don't know if either are possible but hopefully it helps
Locking comments on a site-wide basis rarely goes down well. And the script you described would delete
every comment from that time frame, which would be very, very bad. A script could work if they limited its deletion to the "users" that were spamming the link, however.