You can rinse it again in the tank. Drain what is there, stirring the substrate to make as much mess as possible.
Then start draining. Pull the substrate away from a corner and stick the siphon in that corner. This will pull out more of the fines that are clouding the water.
Partially refill, deliberately splashing in the water to make more mess, and drain again.
You may want to repeat until the water is draining a lot clearer.
The last fill, do this way:
Put a plate or plastic bag over the substrate and run the water in very slowly, allowing it to seep over the edges of the bag.
Do you have the hardscape materials? Driftwood, rock...
Then start draining. Pull the substrate away from a corner and stick the siphon in that corner. This will pull out more of the fines that are clouding the water.
Partially refill, deliberately splashing in the water to make more mess, and drain again.
You may want to repeat until the water is draining a lot clearer.
The last fill, do this way:
Put a plate or plastic bag over the substrate and run the water in very slowly, allowing it to seep over the edges of the bag.
Do you have the hardscape materials? Driftwood, rock...
