FC is BS, please don't suggest to your brother or anyone else as something legitimate or worth trying, esp. for 4-year-old preverbal child who has potential to develop verbal communication, as FC will stop that development when the facilitator makes stuff up that he said, then there appears no need to teach him how to communicate, since he is already supposedly communicating, then he won't learn to communicate due to not being taught how.
The ESL curriculum worked well for me when I learned speaking from age 8 to 9. Learning to read helps provide language foundation for learning to speak or write or type later.
_________________
Drain and plane and grain and blain your brain, and then again,
Propane and butane out of the gas main, your blain shall sustain!