Source: Tafsir al-Ahlam al-Kabir (Ibn Sirin)
Mucus in a dream indicates a child. If it is dry, it is a male child. If it is moist, it is a female. Expelling it indicates the removal of worry.
Source: Ta'tir al-Anam fi Ta'bir al-Manam (Al-Nabulsi)
Mucus indicates a debt being paid. It may also indicate good news.
Source: Al-Isharat fi Ilm al-Ibarat (Ibn Shahin)
Mucus is interpreted as wealth. Whoever sees himself expel it will gain wealth.