The frequency of use of a detoxifying oil depends on the type of work and environments that you frequent. Tends to be used once or twice a week. The beard of a cook, for example, is every day in contact with odors perfumes or vapors or other things that come from cooking something, and with great probability this absorbs the fragrances or very unpleasant smells.
A nourishing oil even if perfumed and used every day can not hide these odors and even probably in the long run worsens the situation. In this case I recommend using a detoxifying oil every day to remove bad odors, and those substances that are absorbed by the skin and beard, so as to keep it clean and away from these situations. After detoxifying the beard you can safely apply a nourishing oil.
For office work or in a closed environment where you have no contact with odors, perfumes or dust or anything else is there that unless there are skin problems such as peeling skin irritation or fungi or other particular problems, There you can safely use a detoxifying oil once/ twice a week and the nourishing oil also every day accompanied perhaps by a brush of the beard before applying the nourishing oil.