Ignored Users only works for the displayed CB. last hour of cb goes unfettered, but maybe the following Greasemonkey script can help with that.

TMTOWTDI. The first /* commented out */ method uses <del> to strike the names and texts. The second deletes the rows entirely.

The included script ignores paco and NodeReaper, two notorious monks that just say the oddest things. Kudos to Tanktalus for the history itself.

Disclaimer: I mostly googled this one together.

// ==UserScript==
// @name cb history Ignore 
// @namespace http://www.example.com/chacham/
// @description strikeout of remove ignored users from last hour of cb
// @include http://perlmonks.org/?node_id=596792
// @grant none
// ==/UserScript==

var ignore = ['paco' , 'NodeReaper'];

/*
// encapsulate in <del>
var author = document.getElementsByClassName('cb_author');

for (var i = 0; i < author.length; i++)
 for (var j in ignore)
  if (author[i].children[0].text == ignore[j])
  {
   author[i].innerHTML = '<del>' + author[i].innerHTML + '</del>';
   author[i].parentElement.parentElement.children[1].innerHTML = '<del
+>' + author[i].parentElement.parentElement.children[1].innerHTML + '<
+/del>';
  }
*/

// remove rows
var table = document.getElementsByClassName('cb_author')[0].parentElem
+ent.parentElement.parentElement.parentElement;

for (var i = (table.rows.length -1) ; i >= 0; i--)
 if(ignore.indexOf(table.rows[i].cells[0].children[1].children[0].text
+) != -1)
  table.deleteRow(i);

[download]

UPDATE: ambrus's comment below seems far superior.

In reply to Ignore monks in last hour of cb by chacham

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.