As already stadate by @banjo @omano and @maycne.sonahoz “Any OS” allows you to completely wipe the disk before install.
If you insist on doing this manually from Manjaro before you install “Any OS”, that is possible by:
- Booting your Manjaro Live KDE USB
- go to KDE Partition Manager
- Right-click the SSD
- Choose New Partition Table
- Choose GPT for UEFI systems or MS-Dos for BIOS-based systems.
- Click Create new partition table
- Apply transaction
- Shut down
- Remove USB stick
Voilà! Completely empty machine!
