Hi Joel, thanks for the reply. No, I'm not talking about a worn out SSD. A worn out SSD is no longer writeable. I have read the link you posted, but that doesn't answer my question. I'm referring to the erasing of previously written blocks. I had hoped that this was becoming common knowledge by now, but there seems to be a lot of confusion about it, and I think SSD manufacturers are exploiting this fact.
To put it briefly, flash memory can be written to quickly if it has never been used. If it has been used, then subsequent writes must first erase before writing. The erase process takes much longer and therefore degrades write performance. As a result of this some manufacturers have released programs such as "wiper.exe" (Google this for more explanation; there are also some long articles on Anandtech explaining SSD performance issues in detail) to allow users to periodically clear previously written flash memory, returning it to "unused" state, and restoring almost full performance. Therefore, any writes will not need to do an erase first. Unfortunately, smaller manufacturers don't provide any utilities for users to do this, so third party solutions are necessary.
I do believe that those utilities provided by the OEMs are low-level utilities that issue the ATA commands directly to the drive to mark them as erased. Eraser doesn't do this, only using the OS to issue writes to the drive and is equal to writing the drive with files. I don't think it is for us to implement this as this makes Eraser hardware dependent. I do believe that Windows 7 does have this implemented in their ATA driver (can't remember where I read this) and that the OS manages it.
I don't think there is going to be one standard way of doing so, save for using TRIM. The SSD is hardware and because each piece of hardware is designed differently there will be no one way of implementing the wipe function. Sure, the post you posted earlier involves using Eraser to write patterns to the SSD, but that doesn't mean that the performance will be restored as to the SSD it may not be any different from writing data to the cell and may not reset the cell, thus in future writing the cell will require erasing it.
You can try to use Eraser to achieve the aim, but it's not something the tool is meant to be used for.