Are you putting your flock at an unnecessary risk? A lot of that depends on where else you wear those boots. If you wear them when you visit other flocks you could track something back to your birds, or you could infect that flock from something your birds have. It's not likely but there is a risk.
If you wear them to chicken shows the same thing could apply but in my mind the risk is reduced. At a show you have a concentration of chickens and people walking around that have chickens so there is some risk.
If you wear them to a feed store again you could pick something up because people that have chickens are walking around there and may have something on their boots. Again I think the risk is pretty low but it's not zero.
That disinfectant thing comes from commercial chicken operations where they have several thousand chickens on site and depend on them to feed their families. Introducing any disease could be a disaster. They generally require their employees to change clothing, not just shoes, before they start work. They generally have pits of disinfectant delivery trucks drive through to disinfect the tires. They take biosecurity extremely cautiously because the potential consequences are so high.
I think I take biosecurity pretty seriously. I have one pair of house shoes that are for only in the house. That's to keep my wife happy and stay married. I have one pair that I only wear when I go visiting or to town. That way I'm not tracking chicken poop into the car, a friend's house, or a restaurant. And I have a pair of shoes I only wear outside, in the garden or with the chickens. I do not disinfect any shoes but I change shoes a lot.
