Fried fillets should be agitated in the milk wash by lifting and lowering the draining basket once.

Fried fillets should be agitated in the milk wash by lifting and lowering the draining basket multiple times to ensure that the fillets are uniformly coated. This technique helps in achieving an even distribution of the milk wash, which contributes to the overall flavor and texture of the dish. Simply lifting and lowering the basket once may not adequately coat all surfaces of the fillets, which could lead to inconsistent results in the frying process. Proper agitation ensures that each fillet is properly submerged and coated, maximizing effectiveness.

The approach implemented with agitation in the milk wash is key to achieving the desired consistency and flavor profile in the final product, which is why the statement asserting that agitation should be limited to just one movement is incorrect.