Disinfectant symbolizes that dreamer is infested, ill or feels dirty in his real life. There are certain parts that are degenerated and “unclean” so they need of cleaning / disinfection.
Also the dream marks that the dreamer is terrified that his soul will become infected which means he’s afraid to get infected by the feelings and passions of others. The dream positively prevents from the contamination. Disinfectant in the dream gives a dreamer a good chance to survive from his emotional injuries and to heal.
Occasionally dream appears for mentally disturbed people who are prone to compulsive cleanliness, often of disinfection.