Note: save cleaning alone will ONLY fix CTDs caused by errant havok objects, in the specific circumstance and using the method Arthmoor already outlined. I put together a tutorial on how to do that on YouTube - hope it helps! :) For this reason I would always recommend a two step process that has saved many a game. Soft Cover Book, 68 Pages, Illustrated, English Text, Clean Inside & Out.

You also need to clean FormID references locked in there too. 1993 Birdwatching in the Desert of Israel Hadoram Shirihai Ofer Bahat PB Book. One point to note is that cleaning scripts from a save is not enough. Once you've removed the mods you think are causing the problem and you want to keep the save going, only THEN does it need to be cleaned. If you are CTDing constantly in a specific area and cleaning temporary FormIDs from your game 'fixes' it, the chances are you have a mod that adds a spawning creature with a broken mesh and the issue will be back as soon as you encounter another of them. I ran a heavily-modded 18-month playthrough and my save sizes were 32MB max - anything more and you have a mod that is bloating the save and needs to be removed. If your save is bloating then you have a mod causing it and will need to look back in your saves to the point your save size changed, then see which mods you encountered in-game when it happened. I would agree that these tools should only be used when you've removed a mod.

Hadoram save game cleaner