What does your template with the Jot comments look like? I’ve just been following up on some comment spammers posting junk to response forms, and looking at my own blog found some entries in old posts had escaped my attention. Apart from deleting the rubbish, I wanted to close older items to fresh comments while preserving the valid comments on them.
My first thought was to produce a second "single post" template - the standard one had this under the post:
<div id="blogComment">
<h4 id="blogCommentTop">Comments ([[Jot?&action=`count-comments`]])</h4>
[+jot.html.comments+]
[+jot.html.form+]
</div>
The idea was to omit
[+jot.html.form+] in the second template, and switch "fossil" items to use it. But a whole template to drop a single line sounded like overkill, so I came up with something much neater, using a template variable assigned to the single-post template.
The TV is defined as type
Radio Options, with options
On==[+jot.html.form+]||Off==(Comments closed) and default
[+jot.html.form+].
The template comment DIV looks like this
<div id="blogComment">
<h4 id="blogCommentTop">Comments ([[Jot?&action=`count-comments`]])</h4>
[+jot.html.comments+]
[*comments*]
</div>
Now I can go back to any old item and select to show the comments form below the already entered comment, or "Comments closed", with a simple click on a radio button. Ain’t MODx flexible?!

KP