It depends on why you're doing it. If the records are "identical to master", meaning they are flagged as changed but are in fact the same as they were before you got to them, then TES4Edit can strip them from your mod all in one go. Otherwise, yeah, you have to go one by one. However, you can also do this in TES4Edit, where it's much easier to see them and get rid of them than if you're doing it via the CS and you have a lot to do.
There are two tuts on the CS Wiki for it, http://cs.elderscrolls.com/constwiki/index.php/TES4Edit_Cleaning_Guide and http://cs.elderscrolls.com/constwiki/index.php/TES4Edit/Mod_cleaning_tutorial_with_TES4Edit. Both are great if you've never used TES4Edit before.
The http://www.gamesas.com/index.php?/topic/1154589-rel-construction-set-extender/ also allows you to mark records as unmodified in the CS without using the "Details" dialog - just right-click on anything in the object list, or in the reference list in the cell window, and choose "Mark As Unmodified" from the context menu. This is the easiest way to catch & fix dirty edits as you work.