However its very important to avoid erecting a Great Wall to the learning experience.
We strongly recommend creating a solid grounding for ALL of your students in the Chinese you wish to use to deliver instructions. Before you start using those instructions.
Consider giving students an opportunity to "be the teacher" in setting up your activities (through Chinese). Using "If you can't deliver it, you don't know it." as your guide to assessing how well they understand.
When each student has had a go at giving instruction through Chinese they'll have better attention and comprehension for receiving and understanding such instructions.