My primary buckets all have spigots. I have a nipple brush I use to clean it. I sanitize by putting the sanitizer in the bucket, run a little out through the spigot, close the spigot. I do this four or five times, then run the rest of the sanitizer through.
Remember one unassailable statistic, as explained by the late, great George Carlin: "Just think of how stupid the average person is, and then realize half of them are even stupider!"
"I would like to die on Mars, just not on impact." Elon Musk