Peter337,
If you don't wish to believe someone who has personally experienced it, perhaps some further reading might help?
So here's one article, for a start:
SKYbrary - Hoar Frost
Here's another, section 2.3:
http://www.atraircraft.com/media/dow...ns_2011_20.pdf
Also here:
http://www.bom.gov.au/aviation/data/.../hwp-icing.pdf