Does anybody have any tips for helping with matted fur on an Essa?

My essa has some spots of sorta matted fur, and even tho I've brushed them with a pet brush multiple times, they just don't go away so idk what to do.

I'm a bit afraid to use fabric softener on it like google is telling me to do because I've heard that fabric softener isn't the best for plushies, so i assumed that a place filled with other people who all own stuffed animals and have probably dealt with a similar thing would know what i should do.