No question is a silly question! Although answers may be silly......LOL!
In the world according to me..."Leave It" replaces NO! in many situations. If my puppy picks up my shoe, I don't say NO! I say, "Eh, leave it!" and I bring my pup something it can have. And I just don't drop the new toy in front of it, I engage my pup in a game with the toy. So it learns my shoe is boring and the toy is exciting. I want my pup to pick up the toy next time. When it does, I'll reward it with an exciting game.
I suppose I could take my shoe and smack it on it's head with my shoe. But really, what am I teaching my pup? That my shoe is off limits and I'm a wicked person? Next time it needs to grab my shoe and hide behind the sofa.
If my pup is out in the garden and it races over for a lovely flower growing in the sun, the moment I realize it is focusing on the flower I'm going to say, "Fido! Leave it!" and I'll have some squeaky fun, furry, rolly toy that makes tons of noise that I know will get my pups attention. I'm going to get on my knees and make that toy go nuts. If Fido ignores me and goes to the flower, I'm going to get up and go right to Fido, re-direct off the flower and onto the toy. Fido is going to think that re-directing is part of the game and my try to go back to the flower. I just repeat "Leave It" and make the toy exciting as possible and try to draw Fido's attention off the flower.
You may ask, "Seriously? Who walks around their back yard with an exciting toy in their pocket?" My answer is; the person who wants to train their pup a specific behavior needs to have all the tools they need to help their pup to succeed.
Hondo Von Dopplet L Bauernhof "Hondo"- GSD
Lilie's Tug McGraw "Tug" - Golden Retriever
Maggie - Mini Dachshund (Rescue)
Lonestar Pivo - Texas Blue Lacy
Ashe - Barn Cat
Katie / APHA