There is no need to use anything other than white distilled vinegar.
I had fungus so bad that several nails were almost completely detached. I applied the vinegar morning and night for a year---overkill I'm sure, but the problem is totally gone.
It takes about a year for the nail to regrow. The treatment doesn't change the appearance of the nail that is already affected by the fungus. It will disappear as the nail is cut over the course of the year or so. The same amount of time is required for the expensive and TOXIC oral treatment.
This vinegar cure is safe and has the very same cure rate as the smelly things you pay a lot of money for. I am sensitive to odors and found it practically odor free.
I bought a small plastic bottle in the travel supplies at the drugstore. The bottle has a push/pull top like some shampoo bottles have. I wet my toes with the vinegar and stood on a towel until they dried and then put on my shoes.
Be sure not to wear old shoes after you cure the fungus, or the it will come right back.