How to teach my 5mo old kitten not to pick things off of the floor and swallow?

Hi there! I have adopted my kitty 2 months ago, when she was 12 weeks old. She is a very shy and a sweet kitty, who eats well and always goes to her litter box (Thank God!). But I have a problem with her picking things habit. I pretty much kitty proofed the house as much as I can. There are still some electrical cords that is very hard to hide and I spray them with a no bite bitter spray.

Because she has this bad habit, I try to vacuum everywhere, everyday. She picks her litter spills in front of her litter box. If she finds something on the floor, bugs, lint, crumbs, whatever you can imagine, if she can grab it easily, she eats it. Once she ate a 3 inch long piece of yarn, right in front of me and I couldn't take it out of her mouth. Once she found a loose staple (Yes, very scary!) and tried to pick it up. Thankfully, I saw her on the action and interrupted her. It it so hard to teach that, this is NOT acceptable. First I tried to grab her slowly and then tried to open her mouth, so she can understand when she does that, she'll be forced to open her mouth. But then I was the one who got scared. I thought this will only teach her not to do it in front of me. Also that she'll get scared of me. So now I don't know what to do. Maybe I am being obsessed and I need to except that she is a cat and this is her nature. But at the same time, I can't quit assuming the worst. If she found something dangerous for her. This makes me so uncomfortable, I always wanna her to be in my sight. That is really hard to do, by the way! Do I need to let her be and grab things? Or do I need to really find a way to teach her that this is not OK? Or, Is this really the right way, following her all the time and keep an eye on her, so I can interrupt her?

Please give me any advice that I can sit on my couch and don't worry about her all the time! Thanks in advance!

I'm sorry, but there shouldn't be a 3 inch piece of yarn or a loose staple around for your kitten to eat, either on the floor or on tables or countertops.You just have to be extremely vigilant at all times and throw away things into a covered trash container and put other things away in drawers.

Of course, mistakes or accidents happen. I accidentally left a card covered in plastic among things on my floor when it fell there. My cat loves plastic, which is dangerous, so I'm glad she didn't find it and chew the plastic.

That yarn was actually coming from one of her toys and when I saw that she managed to rip it, I throw away the toy immediately. And the staple, I still couldn't figure out where did it come from. Like I said, I vacuum everywhere daily. We were in the screened in porch (which I vacuumed and cleaned before I let her there) and maybe she took one out with her claws from somewhere. I checked all the surroundings just in case there are more of those, but couldn't find any other attached ones either. 

I know I have to be extremely careful but that is the reason I do clean the house everyday. On top of that I watch her every move which is exhausting! If I don't see her in the room I am in, I get up and find her to make sure she's not doing something bad. This is not always easy. That's the reason I need some advice, some guidance so I can rest a little bit.

Sorry. It sounds like you're doing a good job. I don't understand the toys that come with long yarn like the one you described. Maybe your cat will stop with time like toddlers do. Best of luck.