Which of these is not included in a primo shampoo?

A primo shampoo is typically characterized by qualities that ensure a high level of cleanliness and care for the hair without causing damage.

When considering the attributes of a primo shampoo, the terms "thorough," "gentle," and "effective" are essential. A thorough shampoo cleanses the hair and scalp completely, removing dirt and product buildup. Being gentle is crucial, as it signifies that the shampoo will be kind to the hair and scalp, minimizing irritation or damage. Effective means that the shampoo fulfills its purpose of cleansing and maintaining hair health.

In contrast, the term "fast" does not pertain to the qualities we associate with a primo shampoo. While a shampoo may be applied quickly, the focus is more on the effectiveness and care during the cleansing process rather than the speed of application. Therefore, "fast" does not align with the primary characteristics of a quality shampoo, making it the correct choice for what is not included in a primo shampoo.