We have a cookie jar but it is filled with dog treats. The dogs are smart enough to know the treats are in it (although likely NOT smarter than your kids, haha), and anytime someone even touches the jar for any reason they get all excited and try to earn one of the treats.
I had to take the dogs over to my parents house for the weekend while we went out to the lake, and I was really glad the husband-type wasn't with me for the drop off/pick up, or I'd be hearing an earful about his "in-laws" and their messy habits. I love my parents dearly, and they have had a really busy summer, but their hoarding tendencies are really out of hand right now and even I was a bit taken aback by how badly their house looks right now (after growing up with them and their chaotic ways). Usually there's a few rooms that are decent-to-acceptable, as far as being able to open/close the door & walk around, or even have some clear space or visible surfaces. There wasn't much of that this time and almost all the rooms are jam-packed with stuff piled up nearly the ceiling, and even the kitchen didn't have any clear counter space and was piled up with stuff. I mean, the trash gets taken out and the dishes get cleaned, so it's not dirty trash, but just STUFF piled up everywhere - toys, clothes, random sewing projects that got abandoned, papers galore... pretty much what all the houses on Hoarders look like in the "before" cleanup images.
When they told me my sister's family was coming to stay with them at the end of the month, I offered some clean-up help if they wanted extra hands for the effort, so that my poor brother-in-law wouldn't have to be staying there with all that mess, as I'm not sure if he's ever seen it that bad. However if it's still that bad when they come, I can guarantee my sister throws a conniption fit about the state of the house, as she always seems much more bothered by it than I ever was.
Polar opposite of MY in-laws, though, who are a military family and would be the type to put plastic covers on the couches. They don't, but they are totally that type of household. Not one thing out of order, not one dying plant or random stack of papers, and I'm almost afraid to touch or move anything there for fear of it being noticed or leaving a fingerprint.