Unlike many conventional martial arts, with preset lists of "official" weapons of their system, the Ninja's art relations on principles and "categories." This is true of its unarmed combat methods, its life skills, and even its weapons like the Ninja's metsubishi "blinding powder."
This article gives a few ideas for substituting everyday objects in lieu of using the ancient "powder" substance itself. In reality, we are not limited by a rigid system of unchangeable "things." If you are to claim your place in the history of the shadow warrior, you must be able to see that the world is filled with tools and aids that you can use for both your defense and your success in every area of your life.
In the case of the Ninja's metsubishi , "sight-removers," Some alternatives to the actual substance include.
1) Water (or any other liquid). If you find yourself holding a glass or cup containing water, coffee, or any other liquid, you can wait until the right moment to throw it into your assailant's face. Again, the idea is to effect the attacker's sight, NOT to use an ancient weapon that has a very limited form.
2) Saliva. Although this could have been included in the previous category with "liquids," this is different in that you do not have to have a container of liquid at the time of the attack. You just collect what you need in your own mouth and then send it out at your attacker.
I know this may sound "gross" or "disgusting." But your ability to think outside the box and do the "unthinkable," really is the key to success and survival against a bigger, faster, stronger attacker.
3) Keys. If you have your keys in your hand when the attacker closes in to launch his assault, rather than holding your keys for striking, you could toss them at him. This tactic, as with all the others can also be used if you need time to go for a weapon but, doing so openly would expose you to greater danger.
It's important to remember that the Ninja's "magic" lies not in the blinding powder of ancient times, but in the strategic use of the principles that make this tactic work. If you understand that it's the timing, and the idea of temporarily blinding or distracting him to cover your own actions, then it does not matter what we use as metsubishi.