joetan

A simple pre-filter to weed out the most obvious comment spam (about 90% of all spam).
Legitimate comments that get blocked (either by this plugin or by Akismet) can be presented with a captcha to confirm that the comment is legitimate. Comments that don’t pass the captcha will be immediately discarded.
Helps you identify potential spam words (you can use this to tweak the plugin’s filters).

TanTanNoodles Simple Spam Filter

A plugin that does a simple sanity check to stop really obvious comment spam before it is processed.

BlashO

Tired of manually cleaning all those spam comments from your blog? You don’t need to work manually anymore. Install this plugin and just schedule – it works for you.
WPSpamComments works in 2 different modes:
Manual Mode: Where you can click “Delete All Spam Comments Now” to remove all the spam comments from your blog immediately.
Auto Mode: Where you have to configure the periodicity (in hours) and click “Schedule Now”. The plugin periodically cleans all the spam comments from your blog automatically.
Go and enjoy blogging, don’t worry about spam comments anymore.
<a href="https://www.blasho.com/wp-spam-comments-plugin/" rel="nofollow ugc">More information from plugin page</a> 
NA

WP Spam Comments from BlashO

Automatically delete and clean all the spam comments from your blog. Just schedule it once.

TanTanNoodles Simple Spam Filter vs WP Spam Comments from BlashO