Yeah got to say I agree with @everittdmickey, mute is your friend. Flagging to me seems like it could potentially harm you in the long run especially if they know a whale lol... unfortunately.
These spam comments are usually why I self vote too, so that it goes to the top and will actually be seen by the author and other people that aren't spamming. Not something I like doing but must be done not to be swallowed into oblivion.