One thing to consider is that you are not "killing" the topical fungus (nails, skin, vagina, mouth etc.), your goal is to inhibit growth of the fungus in tissue that has grown that day during treatment. The growing cells must incorporate some of what is being applied, right into the cell, so that particular cell will no longer be susceptible to the fungus. The natural shedding of old cells and the growing of new, unaffected cells will take place only if you consistently apply treatment twice daily (morning and night).
If a single application is missed, any tissue that grew that day will be susceptible, and the treatment may have to start all over. So resources say that it takes 4 weeks to replace your skin, so if you stop treatment of any skin fungus before 6 weeks, the problem may recur. It takes at least 6 months to grow an new toenail, so if the treatment is stopped less than a month after the nail looks normal, the problem will likely recur. Fungi abhors an acid environment. The normal colon contents are very acid which is what normally protects us from having Candida issues.
So, keep in mind that the toenail will have to grow the infected nail off the body. If treatment is missed for even one single time, the nail that grew that day may not be resistant to the fungus, and the fungus can infect the new growth (since you are not killing the fungus - you are inhibiting it from attaching itself to the new growth). Likely, the treatment time starts all over when you miss a treatment.
The protocol for a toenail fungus should be:
Apply a couple drops essential oil at the growing base of the affected nail every morning and night, and within a few months, a normal nail should begin to show at the base of the nail.