There are two brushing methods that can be used; Soft pressure and moderate pressure. When moving apically to coronally you want to brush softly. When moving coronally to apircally you want to apply more pressure when brushing. You can begin brushing when the full thickness of the flap is elevated, making sure to brush as deep as possible.
Pull the flap back with forceps and start brushing with the small size (regular or angulated for the posterior area). After the first release you can use the medium or large for large flap areas. This allows you to extend flap significantly with minimal trauma. In the lingual flap, it is very easy to separate the mylohyoid muscle very gently by just brushing. It is also possible to brush the periosteam of the lingual flap.
Take the headache out of flap surgery and increase your ability to gain primary closure with the soft brushing kit.