this shampoo is the type to use once weekly right?
IMO, I wouldn't say that its once a week for males. For females, yes some of them choose to deep cleanse once per week because they don't perspire that much as compared to males. Deep cleansing basically stripes off the oils from the hair and it will tend to feel dry, which females typically will not like to experience. This is especially so if the hair is long and it will take further efforts to moisturize it well enough to look silky smooth and light. This, however, isn't a major concern for guys which explains why males, and not females, choose to deep cleanse more than once a week. Personally, i deep cleanse on alternate days which is just nice for me.
All in all, deep cleansing is actually essential. Some might even bring it further by taking good care in moisturizing it well enough. If you don't moisturize it, the hair will produce even more oils which will make it greasy. Now, who will like their hair to look oily?