Is there any medications for difficulty of swallowing when the client have bell's palsy? or soft diet recommendation are the only treatment to restore loss of electrolyte imbalances?

Bells Palsy can be a temporary condition that will go away on its own. Occasionally oral steroids are used to reduce the inflammation. The use of a soft or liquid diet during this time prevents damage to the esophagus and aspiration. There are no medications that will specifically fix the difficulty swallowing as it is a function of the nerve being compressed due to inflammation.

A classical Bell's palsy affects function of Nerve VII solely, and does not impair swallowing which would involve different cranial nerves. If you do have such issues, this suggests a more widespread problem, especially if accompanied by "electrolyte imbalance. See your doctor ASAP, as there is more going on than just a Bell's palsy.