In the iodoform test why is it necessary to add sodium hypochlorite

Sodium hypochlorite is used in iodoform test for the oxidation of alcohol to aldehyde as shown in the image attached:

Here sodium hypochlorite is formed by the reaction of NaOH with I2 that further oxides alcohols to aldehydes.

it's filtration, but this is an assumption so my apologies if i got this

a  solution  is always transparent, light passes through with no scattering from solute particles which are molecule in size. the  solution  is homogeneous and does not settle out. a colloid is intermediate between asolution  and a  suspension. while asuspension  will separate out a colloid will not.