To some extent, yes.
Toxic substances entering the body can be found in the aforementioned secretions. However, the most significant role in eliminating toxins is played by sweat: intense sweating, accompanied by adequate fluid intake, can somewhat reduce the impact of moderately toxic substances such as alcohol.
Sweat also partially removes the end products of nitrogen metabolism, while ear secretions help eliminate excess wax. Nevertheless, these products are unlikely to be considered toxins. Mucus produced by the respiratory tract aids in the removal of dust and microorganisms that enter the body with the air. As for dandruff, which consists of flakes of dead skin, it is a pathological condition indicating problems in the functioning of the scalp.
