I'm sure that I tried to block forum posts with AdBlock/Adblock Plus before, but without success. So they have either updated their applications to make it easier, or I have just been more determined this time, because I have managed to get it to work.
I have the latest versions of AdBlock & Adblock Plus on my machine, so if you have older versions, this may not work.
Whichever of these applications you use, you will have to add custom filters to block posts and quotes.
From the AdBlock icon on your browsers toolbar, select options, then, for AdBlock, click the Customize tab, and for Adblock Plus, click the Advanced tab.
In the manual filter boxes, you should add the filters below (blue text).
The first one is to block posts and the second one is to block quotes. Where it has 'scotthope' and 'anothername' between the forward slashes in the brackets are examples. You can put the name/s of whoever you want to block between those forward slashes, but if you have more than one name, each name must be separated with a pipe '|' character.
I wouldn't advise the editing of anything outside the forward slashes '/', unless you understand the construction AdBlock's custom filters. The filter is not case sensitive so you need not worry about capitalization when entering names into the filter...
The blockquote filter removes the entire quote. I would've preferred it if the quote box was still in place without the text, but that is proving difficult for me, so the whole quote gets removed at the moment...
There is another post HERE showing how to add a custom filter to AdBlock.
Custom Filter Documentation