(adsbygoogle = window.adsbygoogle || []).push({}); I want to make a clean reflash from 0 , I know sometimes after reflashing I see programs and settings I had before , I am on CFW 4.75.3 drex .

To reformat?

1. put ps3 in recovery mode
2. select option 5 i believe "restore ps3 system"
this will reformat your hard drive and bring you to a black screen asking you to install your last firmware x.xx whatever it was
3. reinstall your cfw
You will need to reinstall ccapi and possibly some other stuff.This will wipe your games, saves, settings, everything, but you will still be jailbroken as long as you choose to install cfw.

I found out that formatting hdd with a computer (fat32formatter) it will purge all data and info stored on it , because with PS3 system after reflash you still have same settings in debug settings and others ....

This is true