Is it permissible to return to masturbating twice a week to stop watching pornography, or are there other ways to quell desires?

It is not permissible to masturbate or to watch prohibited videos. One must repent from these two actions and adhere to Allah's Sharia.

What aids in this is adhering to the obligatory duties, increasing fasting, frequent supplication, keeping company with the righteous, avoiding everything that arouses desires, and occupying one's time with beneficial activities.