The software can be downloaded here
Free for 14 days, after that it's €20. (still ?)
Example of a filter that works pretty well, derived from the predefined filter named Cyborg
The filter: CyborgStronger.zip is to be unzipped and imported into Voxal via the “File>Import Voice” menu
The filter settings:
This filter disguises the voice well, but it is not irreversible enough. Indeed, by applying a pitch shifter of 1.25 (=1/0.8) we recognize the voice very well.
Contact me to get an example of a more irreversible filter. Logically, I am not putting it online.
A bug: the Voice Pitch Shifter filter: do not edit the % value by hand, change it only using the slider. Otherwise, crash during transformation.