ECU Virginizing is similar to ECU Cloning.
ECU Virginizing is a procedure where a known good, used replacement ECU is reconfigured into a like-new or “virgin” state, also known as “renewing”.
The ECU can then be used to replace the original, but requires coding using the original diagnostic tools.
ECU Cloning is a procedure when the original ECU information is copied to the replacement ECU, and allows it to be reused. Original diagnostic tools are not required to complete the re-installation.
IMMO delete is the last resort if both options didn’t work or too expensive. It will program ECU to no security state.