At least the one i used, power delete suite, doesnt need API access, its a script run while youre logged in, they said if you can delete comments, it can delete comments.
They probably can be switched to scraping instead of api, will be slower but should be ok if you massdeleted everything already and just do like a daily/weekly cleanup of a few comments.
Unfortunately the tools for mass editing and deletion will probably stop functioning on July 1.
save