I'm sorry perhaps I didn't explain sufficiently. I have no problem repartitioning. I want to secure erase in order to return the SSD to factory condition, i.e. so that there are no blocks with data in them that the garbage collection routine thinks is valid data. If I don't do this the performance will suffer. Diskpart talks about "zeroing sectors" without a proper explanation of what that means. If it means writing zeroes in all locations, this would have quite the opposite effect of erasing the blocks since zero is valid data not the same as an erased state. Of course you will know this, but I want to make it absolutely clear.
So the proper solution is to do a secure erase which erases all locations. The problem is that the design has made it impossible to do via the Intel toolbox because the SSD is in a security frozen state and no amount of hot-unplugging and plugging will release it.
The help files say that if this repeatedly fails to unfreeze the SSD, the Intel Toolbox cannot do this and they suggest finding an independent tool to do it. This is a cop-out and is in my opinion quite deplorable, Intel engineers should have found another way, but there's no sense in me ranting about it, I just want a solution. I asked a valid question in the original post which has not been addressed.
I appreciate that you didn't realise why I wanted a secure erase. Hopefully I have explained that now. Could you please revisit the original post and offer a solution.