My understanding is that Tazer's, stun guns, mace and pepper spray are not legal here in Mexico. I think this is so because these items are described as intended to be used similar to a weapon and you cannot carry a weapon, even a club or or knife. Depends on who you ask what answer you get. I do know that a friend was detained a couple of days because she had pepper spray in her purse. I do know that I was stopped a couple of years ago and had to pay a fine because I had several knives in the truck and no it was not a curb fine, I went to court.
This is why I keep a can of fast discharge wasp and hornet spray handy, in the vehicle, home and office. I have a serious problem with these pests. Perfectly legal and very effective. Just don't say you carried it for self protection. It just happened to be handy. The smell is enough to disorient someone, you don't have to spray it directly in their face. The bit about blinding someone might be a problem in the US, but it would be the same if you shot them and did not kill them outright. Reasonable force is a post event determination open to interpretation so the lawyers love it. There was a time in my life that I got death threats and was told then by local law enforcement to shoot them on the porch and drag the body across the doorstep but to be sure to kill them not wound them.