OK, I think this should work: create a plugin using hook parse_templates and code like this:
Code:
$ishout_rules = addcslashes($vbulletin->options['ishout_rules'], "\r\n'\\");
Then in your template:
Code:
var RULES = "$ishout_rules";
This won't change the newlines to <br>, but if you are allowing html in your rules then the person writing the rules should put <br> where they want a newlines.
By the way, you asked about how to access a variable in the other thread and I'm sorry it didn't occur to me that you might have problems like this with a string.