I'm not sure your concept is correct. Just because a file is deleted, doesn't mean that when a new file of the same name is created, it overwrites the old one. In the case of the swap file, or in later Win versions, paging file (pagefile.sys), the Windows feature for deleting the paging file only makes one pass of writing zeros - or so I've read.
If you physically delete the swap file (like c:\pagefile.sys), then Windows creates a new, empty one at reboot. But, the new one is not necessarily, and most likely will NOT be written on top of the old file (which still exists on the disk because it wasn't securely erased).
Besides that, the new empty paging file has nothing in it to completely overwrite the old one, even if it was placed in the exact spot where the old paging file was - which it probably will not be.
As I understand it, either live w/ Windows' level of security of overwriting the file w/ one pass of zeros, or delete the file and then erase the free space on the drive or partition where the paging file was.
No, Eraser doesn't erase the paging file in Win 2000 / XP. It only enables the function that already exists in Windows to overwrite the paging file. But, you can enable that feature w/o Eraser.
For Win XP, see How To Clear the Windows Paging File at Shutdown http://support.microsoft.com/kb/314834/en-us