Understanding, like a should scientist
You can’t stop others from shoulding. That is like shoulding on top of shoulding. All you get it is more should. Instead, try these tactics:
You can ask them to stop shoulding. “When you tell me what to do, it makes me feel ….. and what I need is space to think.”
You can accept their should with the hopes that it will stop it’s further piling. Example “Thanks, I never thought of that.”
You can ignore their shoulding. This involves not feeding into it and instead focusing on the things that you would rather put energy into as well as tending to your presence, should free.
Maybe their should has some recycling value?
You could develop an online course to help them come to the conclusion to should less.
You can point them to this said online course. No warranties or guarantees.