If the fungus creeps back, this means you are not healed yet. Gttin rid of the Psoriasis is phase one of the fungus cleanse. It is actully said that once you are symptoms free altogether, you should carry on with the diet for another 3 months in order to get rid of the fungus completely.
As long as you still need to use antifungals, you have not healed yet.
Still, you are right, the diet alone will work on the long run. But you will heal faster if you use Bowel Cleanse (psyllium husk) and liver cleanse (olive oil and lemon juice).