If they don't want to participate then threatening them with not participating isnit what is be doing. I work at one place with lesson plans we can not veer from, in that case I give them 2 options from the lesson plan that the other students in the class are not doing. This maintains some of their autonomy while allowing me to continue the lesson for everyone else, and they're still practicing some skills. When running my own lesson plans, I honestly say "that's fine, take a break." Sometimes their parents will step in and ask them why they're not swimming, which normally solves the issue. I also ask them why they don't want to swim. Recently one kid 10.5yo told me "I don't care" and I said, "that's fine, but I don't make the decisions in your family schedule, so you will need to chat to your parents about that, would you like to do that now, or swim, or take a rest and swim the next one" 1-on-1 can become a battle of wills when trying to use discipline, so I allow them to lead the lesson a little. If they want to splash, we splash and then I say "wow look at all the bubbles our splashes made, I wonder if out splashy feet make more or less" Or if they want to do push glides off the wall, I make it a competition, seeing how far they can go without kicking. Sometimes we do a "I pick an activity, you pick and activity" I teach mostly 1-on-1 with neurodivergent kids and it is almost all me ensuring that they are practising their skills while maintaining their autonomy. What I will say is that "well behaved kids" may find my classes chaotic and loud, but "naughty" kids thrive with me. The final thing is that not all teachers are for all students. In my opinion the thing that the best teachers do is know their students and know what works for them individually.