I used cinnamon once, a long time ago. I covered the whole of the pot with a thin layer of the stuff. From what i remember, it didnt help the plants one little bit.
The best thing for fungus would be some sorta sulfur-based fungicide, which is safe on CPs.
Try the cinnamon, if you want, i could have done it wrong or been unlucky with it.

Sprinkle cinnamon on the surface and/or manually remove the mold.

Thanks guys/girls.
I do have sulfur in the house .I bought it years ago because someone said it would help with fungus. So I went to a chemist's and told her what I needed and why. But when I opened it later on there were no instructions on how to use it. Some people told me to put some in a saucer and put the saucer next to the plant with fungus , others told me to spray it over the plant(I tried that, it died).
So now the little container has been sitting there for a couple of years without being used because I'm not sure what to do with it.

When you put seed/moss mixture in the fridge to give the seeds their cold period,would it be helpfull to put some cinnamon in the mix to avoid fungus forming?
Would living s-moss do a better job to stop fungus creeping in?

Although the key ingredient in cinnamon bark, cinnamaldehyde, is a good fungicide, you should limit the amount you use. Cinnamon bark contains traces of iron, calcium, manganese, and probably additional trace minerals which your plant may not appreciate.

My last batch of Sarr. seeds I had in the fridge ,I put in some rainwater to pick them out of the moss they were in. This way it was easier to put them on top of the mixture I wanted to plant them in. I guess if I do this again with future seeds I might try a little cinnamon in the fridge mix , it would be washed off before I plant them.

Cinnamon can work really well if you use enough
be very careful of sulfur bases fungicides if you have your plants with orchids, sulfer based fungicides will kill some species/genus of orchids, like dendrobiums and the catasetum alliance