This got removed about 12 years ago
https://sourceforge.net/p/web-erp/code/266/#diff-10 not sure why, the commit message is not particularly helpful.
I would be careful when using any of the delete Z_*.php scripts especially on a production server.
Firstly because many of them are old, and haven't been properly maintained - there isn't really any change to the logic of the scripts in over a decade whereas the code itself has moved on considerably so inconsistencies can happen.
Secondly, as an accountant I have an inbuilt dislike of removing a transactions that form part of the history of the ledgers.
Tim