If I had to choose and add one more factor to Dr Klenner’s protocol that would definitely be exercise techniques which an MSer should choose according his capabilities and limitations and may be adjusted during time. Exercise is not about building muscles and overdoing it. Many people believe this. Also many people underestimate the value of exercise. There are many techniques which have to do with stretching, breathing (yoga),  Pilates, pnf, tai-chi, aquatic exercises or classic physiotherapy.
It wouldn’t be wise though to suggest something about all of the above to patients because this is something you should decide.
We just say that it is impossible to get all the benefit from Dr Klenner’s protocol if you leave your self go rusty especially if you have been facing mobility issues for long or you have adapted a wrong kinetic model because of your symptoms. Spasticity for example may create stiffness and this will result in a difficulty to move. Difficulty to move, in long term basis, will result in adopting a different kinetic model without noticing. This usually has an impact to muscles. Some muscle groups are left unused and some others are getting over tired.
You may have achieved much more progress than you think with the protocol but you’ll never know it if you don’t have a specific daily if possible exercise program to “re-program” your brain to learn how to give the right commands to your body… Keep in mind that our brain never forgets…
Also avoid at any cost swimming pools which contain chlorine and find one with ozone.
For the rest we just quote a very informative article and a video taken from nationalmssociety.org which clarifies things:

In addition to being essential to general health and well-being, exercise is helpful in managing many MS symptoms. A study published by researchers at the University of Utah in 1996 was the first to demonstrate clearly the benefits of exercise for people with MS. Those patients who participated in an aerobic exercise program had better cardiovascular fitness, improved strength, better bladder and bowel function, less fatigue and depression, a more positive attitude, and increased participation in social activities. Since 1996, several additional studies have confirmed the benefits of exercise.
Inactivity in people with or without MS can result in numerous risk factors associated with coronary heart disease. In addition, it can lead to weakness of muscles, decreased bone density with an increased risk of fracture, and shallow, inefficient breathing.
An exercise program needs to be appropriate to the capabilities and limitations of the individual, and may need to be adjusted during time. A physical therapist experienced with the unique and varied symptoms of MS can be helpful in designing, supervising and revising a well-balanced exercise program. Any person with MS who is initiating a new exercise program should also consult with his or her physician before starting.
Periods of exercise should be carefully timed to avoid the hotter periods of the day and prevent excessive fatigue. With some guidelines, a good exercise program can help to develop the maximum potential of muscle, bone and respiration, thereby avoiding secondary complications and gaining the benefits of good health and well-being.”

Taken from:nationalmssociety.org

Watch the Video