The notion that it takes 24 hours to dissolve and equilibrate a fresh batch of saltwater is not because salts take a long time to dissolve. They dissolve quickly.
You do want to equilibrate the new salt water with atmospheric CO2. This takes hours with good aeration not days.
The other thing that happens in 24 hours is that a small amount of insoluble material settles out. This stuff can sometimes be seen sticking to the bottom or sides of the bucket. I would guess the amount varies from batch to batch and from brand to brand. I would also guess this is why aquarists using the 24 hour or longer method never see the cloudiness problem.
You do want to equilibrate the new salt water with atmospheric CO2. This takes hours with good aeration not days.
The other thing that happens in 24 hours is that a small amount of insoluble material settles out. This stuff can sometimes be seen sticking to the bottom or sides of the bucket. I would guess the amount varies from batch to batch and from brand to brand. I would also guess this is why aquarists using the 24 hour or longer method never see the cloudiness problem.