Yea, thats an old wives tale, dont work
This isn't medical advice, but the active ingredient in Visine eye drops is Tetrahydrozoline HCl 0.05%. Swallowing this substance can result in a number of nasty effects, including:
* Lowering body temperature to dangerous levels
* Making breathing difficult, or even halting it entirely
* Blurring vision
* Causing nausea and vomiting* Elevating and then dropping blood pressure
* Causing seizures or tremors
* Sending the ingester into a coma
Additionally, the Saline in the solution can actually cause mild to moderate diarrhea or vomiting. I know this one first hand after a trip to an area in the far western edge of Texas about 4 years ago. Before going to bed at my friends house I drank 2-3 glasses of tap water. I woke up about 3-4 hours later with a certain urgency to head for the bathroom. Needless to say, for the next 4-5 hours I could not be more than 50 yards from the toilet. My friend, a medical doctor was concered and thought I might have food poisoning. We were actually about to head to the hospital so he could get me a shot, when I went in to the kitchen to get a glass of water. He saw me turn on the tap and said, 'WAIT! You probably shouldn't drink that." He then told me to drink the water from the water cooler they own instead. I asked why and he replied, "Our ground water in this area has about 300%-500% more saline in it than most places and it could cause you even more gastric problems." I set the cup down and asked him what drinking 3 glasses and then falling asleep would do. He started to laugh... Me, not so much...
Of course, either one of those chemicals is going to interact, but it will totally depend on:
1. The amount ingested.
2. The persons body weight
3. The persons metabolic rate
4. How much Saline is that person used to ingesting
5. How much other food was ingested, and what types of food (Some foods could neutralize the affect of the Saline).
You'd be better of using Contact Solution as that doesn't have the nasty Tetrahydrozoline HCl .
At least then you would know you aren't possibly going to put someone in a coma.