Mark Jaquith

This simple plugin inserts the following into the comment form:
<blockquote>
Not <code>USER'S NAME</code>? Click here to clear this info.
</blockquote>
When clicked, the comment cookies will be cleared, and the form will become empty. This only shows up if the user is not logged in (as most comment forms have a “log out” link for them), and if the user has a comment cookie.

Forget User Info

Inserts a link into the comments form that will clear a user's comment info cookie

UpNext Innovate LTD

UpNext Cookie Notice is a lightweight plugin that displays a simple cookie consent message on your website. 
This plugin does not list individual cookies – it provides a general consent notice only. 
Easily customize the message text, privacy policy link, button text, colors, and display duration from the WordPress admin settings.

UpNext Cookie Notice

Simple cookie notice plugin for WordPress, allowing site owners to display a customizable message about cookie usage.

Forget User Info vs UpNext Cookie Notice