Snake charmers

8 Then the Lord said to Moses and Aaron, 9 “When Pharaoh says to you, ‘Prove yourselves by working a miracle,’ then you shall say to Aaron, ‘Take your staff and cast it down before Pharaoh, that it may become a serpent.’” 10 So Moses and Aaron went to Pharaoh and did just as the Lord commanded. Aaron cast down his staff before Pharaoh and his servants, and it became a serpent. 11 Then Pharaoh summoned the wise men and the sorcerers, and they, the magicians of Egypt, also did the same by their secret arts. 12 For each man cast down his staff, and they became serpents. But Aaron's staff swallowed up their staffs. 13 Still Pharaoh's heart was hardened, and he would not listen to them, as the Lord had said.

Some conservative commentators interpret the action of the Egyptian magicians naturalistically. They say it's a parlor trick. If you pinch a nerve at the back of its neck, that will immobilize the snake. It will become rigid, like a rod.

Although that's a possible explanation, that's easier said than done. To begin with, the magicians didn't have advance knowledge that Aaron was going to do this. It's not as if they had supply of cataleptic snakes on hand to perform this stunt–if that's what it was. 

Assuming these are venomous snakes (e.g. cobras), how to you induce paralysis without getting bitten in the process? 

I've seen nature shows in which a herpetologist (or just a brazen daredevil) will pick up a venomous snake by the tail. For that to work, you have to keep the snake at arm's length from your body. The snake must be short enough that it isn't scraping the ground. It must be vertical to keep it at a safe distance. If the snake is long enough, it can bite you in the foot, leg, or between the legs–something men are eager to avoid. You don't want that head level with limbs and other appendages. 

But a snake that's the length of a walking staff would be too long to hold by the tail, and keep the entire body of the snake in the air. Herpetologists use snake hooks to keep the head away from their body. 

Another problem is that when you grab a snake by the tail and lift it up, the head and neck can assume a horizontal angle, which puts the handler in striking distance of the snake.  I've seen handlers shake a snake by the tail to keep the head down. Keep the body straight. 

This is very dangerous, but even if you can avoid getting bitten by grabbing and holding a snake by the tail, I don't see how, from that position, you immobilize the snake, since you are holding the wrong end to do that.

I've also seen nature shows in which a herpetologist milks a snake. But he doesn't grab the snake with his bare hands. Instead, he uses snake tongs to catch it by the neck, pin it to the floor, then gingerly grasp it just below the jaws. Even so, that's a very risky procedure. There's no margin for error. This is usually done in a setting where there's antivenom nearby. I've read about herpetologists who died when they tried to do this out in the bush. One slip, and they were goners. Did ancient magicians have aluminum snake tongs? Don't think so. 

Finally, I've seen herpetologists hypnotize a king cobra in the wild to tap it on the the head. Perhaps that's a possible way to grab a snake by the head without getting bitten, then induce paralysis. But there's a high risk of snakebite. 

In addition, I've only seen that done with king cobras. Would the same trick work with smaller cobras? Are smaller cobras more easily agitated? 

Of course, I've seen snake charmers (on TV) with cobras. But that can be deceptive. When they handle cobras, I've read they stitch the mouth shut. And the snake will die in a few days from infection. 

Nowadays, the snake may be defanged. But that requires surgical tools. Moreover, snakes rapidly replace lost fangs.

The Egyptian magicians didn't have the lead time for these precautions or preparations. Within the implied time frame of the story, how would they capture snakes and immobilize them in time to counter Aaron? 

Moreover, surely no one would mistake a rigid snake for a staff. If the magicians come out holding cataleptic cobras, which they cast on the ground, can't anyone see these were snakes all along? 

An unbeliever might say these are plot holes in fiction, but if it were fiction, there's no reason to offer a naturalistic explanation.