As well as this being a hypothetical...err, what do you mean they look perfectly innocent? I'm not even sure what this phrase means.
You don't just randomly put s*it in your mouth because it "looks innocent".
If I saw a colourless liquid on a table, and I didn't know where it was from, I wouldn't just randomly drink it.
Likewise with just randomly picking up plastic bits and eating them.
However, if you're talking about young kids who are liable to put anything in their mouth, then "looking innocent" doesn't even enter into the equation.
As a parent, you should be looking after your kids, and childproofing your house - you wouldn't put scissors on a table, or a kitchen knife within reach, or bleach or other household cleaning liquids, or a hammer, or nails.
And you wouldn't let them unattended near a swimming pool, or let them near the stove in the kitchen, or let them walk in a park without supervision.
All of these are basic parental responsibilities - I don't see how these magnets are any better or worse than letting your kid eat a staple, or a nail etc.
I mean, as a kid, I shoved a lego up my nose (yeah, I was a smart cookie), and had to be rushed to the doctors.
Another time, I nearly ate dog poo.
Did both of those things (lego and go poo) look "innocent"?
These things happen. An ex-girlfriend's 8 year old (at the time) swallowed two small kitchen magnets (they were the small type embedded in what looks like a push-pin top). At the time it was suggested by the doctor that he might have had pica (http://kidshealth.org/parent/emotions/behavior/pica.html) and that's why he ate the darned things.
You don't just randomly put s*it in your mouth because it "looks innocent".
If I saw a colourless liquid on a table, and I didn't know where it was from, I wouldn't just randomly drink it.
Likewise with just randomly picking up plastic bits and eating them.
However, if you're talking about young kids who are liable to put anything in their mouth, then "looking innocent" doesn't even enter into the equation.
As a parent, you should be looking after your kids, and childproofing your house - you wouldn't put scissors on a table, or a kitchen knife within reach, or bleach or other household cleaning liquids, or a hammer, or nails.
And you wouldn't let them unattended near a swimming pool, or let them near the stove in the kitchen, or let them walk in a park without supervision.
All of these are basic parental responsibilities - I don't see how these magnets are any better or worse than letting your kid eat a staple, or a nail etc.
I mean, as a kid, I shoved a lego up my nose (yeah, I was a smart cookie), and had to be rushed to the doctors.
Another time, I nearly ate dog poo.
Did both of those things (lego and go poo) look "innocent"?