How to do a Knock down Ceiling
This takes some prep and a sprayer which is pretty inexpensive. But it's messy!
Wagner Power Tex Sprayer https://amzn.to/2U172Xw
HYDE 09997 Acrylic Knockdown Knife https://amzn.to/3c6UDIT
Make sure you clean this thing out with hot water immediately afterwards or it won't work well the next time.
Have Fun!