I’ve had a lot of success clicker training our cat too, I have yet to directly apply it to being quiet but I’ve also noticed as the way I prepare food changes, the response does too. For example our cat used to eat dry food and had an immediate response to the bag and the sound of kibble pouring, even after switching to wet food due to having some teeth removed. But the more I handle dry food when it’s not feeding time, the response is reduced. I also sometimes prepare the food 20 minutes in advance but let it sit in a safe place (for us the counter is safe), then I surprise her with the food dish at feeding time. This also seems to reduce meowing, so I plan on continuing to separate the sounds of food being prepared from feeding time to see if I can get her to both not have an opportunity to know in advance when food is coming but also to lessen the association between the preparation sounds and food being imminent.