Rinsing with water should follow the antichlor treatment in order to flush out by-products of the procedure.
Hydrogen peroxide is by itself a strong bleaching agent and should be used only in diluted form, such as a 3% solution in water.
Hypochlorite plus peroxide releases triplet oxygen, which is itself a bleaching agent, but is short-lived in water solution.
Reacting large amounts of peroxide can release enough oxygen to create a fire or explosion hazard.
Antichlors are sometimes added to shampoos for treating hair after swimming in chlorinated water.