Fungus on cuttings

This is my first attempt at sticking cuttings of tropical Hibiscus. What can I spray on the cuttings to stop the white fungus that is growing on some of them?

I have always used a mixture of peroxide and water. Get the 3% hydrogen peroxide and add 2 1/2 tsp per gallon of water. I have had it work as quickly as 2 days by putting it in a spray bottle and misting the cuttings with it. They also say it is good for preventing root rot, but I have never used it for that purpose. I used it on seedlings, cuttings and plants where mold started growing on the dirt.

I'd also watch how wet you're keeping the cuttings...fungal growth could mean you're keeping them a bit too wet.