When I was about twelve years old, I licked a cactus. It was a small cactus whose spines were so fine that they looked more like a coating of downy hair than real thorns. When they wouldn't stick to my fingertips, I decided they probably weren't thorns at all, but, just to make sure, I stuck my tongue to the cactus. Well, fingertip skin is tough. Tongue tissue is soft. Little tiny cactus spines won't stick to fingers, but they will stick to tongues. Take my word for it. Do not feel like you need to repeat the experiment. The results would probably not be appreciably different.

I have never licked razor wire.