Skip the long YouTube videos and the demineralized water. Try soaking the filter in white vinegar for a few hours (or overnight) first.

Our BeFree filter stopped flowing after 1.5 seasona. We backflush our filter and clean with bleach before storage so we thought maybe it was dried out. We went the entire SCT shakedown without filtered water (and used chemical treatment or boiled water instead).
As a last ditch effort we soaked it in a cup full of white vinegar for a few hours and the flow returned to normal.
It’s worth a try if you are about to toss yours in the trash. We had vinegar in our apartment, but not demineralized water, so this was something we were able to do easily without spending money on a filter we might need to throw out.