According to https://docs.joomla.org/Using_caching_to_speed_up_your_code ,I must use
$cache->cleanCache(); if I want to clear the joomla cache in my custom script.
That function throws the error "does not have a method cleanCache".
As far as I could see in the API, the new method is called "clean". However, that also doesn't clear the cache (I can still see the cache files via ftp).
Is is something that is broken?
I am using Joomla 3.7.3