Yes I know, but if you want to avoid the cloudiness, then don't listen to the instructions. 😄
There is no right way or wrong way to switch substrate. Just do it the most efficient way you can manage.
For some, it's catching everything and draining the tank. For others, it's scooping out the old gravel as much as possible and replacing it with new gravel slowly without crushing/burying the little shrimps.
I usually catch the shrimp, drain the tank, and replace the substrate. Either way be prepared for a long process.
What Grubs said.
DAS is a little bit more colourful as well. You can get them at Aquagreen but just remember, they need brackish water and the plankton in it to breed. Or more accurately the newly hatched young need brackish water.