In the United States and perhaps elsewhere, there is a common misconception that the poinsettia is highly toxic. This is not true; it is mildly irritating to the skin or stomach and may sometimes cause diarrhea and vomiting if eaten. Sap introduced into the human eye may cause temporary blindness.
Even with the myth cleared up, the idea of it causing temporary blindness is interesting. Further reading has lead me to the understanding that it’s not a reliable result, but something equivalent to a can of mace that doesn’t induce pain, but instead causes short-term loss of sight, (or even both,) might be quite effective.
Honestly, I’m sort of a fan of devices that encourage people with criminal intentions to seek professional medical treatment for non-life-threatening ailments – like the Rape-aXe.
If an attacker were to attempt vaginal rape, his penis would enter the latex sheath and be snagged by the barbs, causing the attacker excruciating pain during withdrawal and giving the victim time to escape. The condom would remain attached to the attacker’s body when he withdrew and could only be removed surgically