Final answer:
The positive pole or anode in facial treatment primarily provides a germicidal effect, benefiting skin health by purifying and detoxifying, which is particularly helpful for acne-prone or oily skin types.
Step-by-step explanation:
During a facial treatment, the application of an electrical current can have various effects on the skin. When using the positive pole or anode, one of the primary benefits is the germicidal effect. This effect is due to the production of oxygen, which creates an environment that is inhospitable to anaerobic bacteria. The oxygen also helps to purify and detoxify the skin, thus aiding in the prevention of acne and other skin infections. This germicidal action contributes to overall skin health and can be particularly beneficial for those with acne-prone or oily skin.
While the anode does stimulate nerve response and has been observed to have some effect on softening debris in pores, these are not the primary functions of the positive pole in electrotherapy treatments. Desquamation or the shedding of the outermost skin cells is more directly related to exfoliation treatments rather than the electrical aspect of a facial.
Therefore, amongst the given options, the correct answer for the beneficial effect of using the positive pole (anode) during a facial treatment is a. germicidal effect.