On Arsenic and Spoons

I was thinking just now, about the role of royal food-tasters. You know, waaaay back when royalty had people at the table to taste their food, and if they didn't die it wasn't poisoned? (I wonder how many roasts grew cold while they waited around...) 

Well, I was just thinking, wouldn't it be easier if the saboteur in question simply dipped the King's cutlery in the poison of choice? I mean, granted you didn't choose a chemical that would turn the silver green, or set the table smoking, wouldn't this mode of assassinry be ideal? You could set the table hours in advance, with most life-threatening chemicals, and they would still be active when the Royalty unsuspectingly set spoon to soup. After all, it's not like the food-tasting servant would have the audacity to use His Majesty's silverware. Wouldn't that be infringement upon the royal lips or something? In a day where a kiss from the King upon your baby's forehead was forever a blessing, I think licking the royal salad fork would be considered quite the offense. Off with his head! 

It's rather perfect, really. I wonder if it was ever tried?