Always consult with your doctor first, and if you can get a pulmonary physio to show you how, all the better, but I, and many others, believe that daily airway clearance is the number one in keeping the lungs as clear as they can be. There are links on Mayo Connect and several on YouTube. Different techniques work for different people. It is the one thing that I will continue for the rest of my life. There are no pulmonary physios in my area, so I had to use YouTube.
It is also worth checking out with your pharmacist regarding supplements (zinc & or copper) to take while on Ethambutol. They will know what and when you can take something. Always check any advice with the professionals!