You absolutely DO NOT want to mess with chlorine dioxide. It is seriously dangerous stuff when it is not properly handled and dosed and you could easily hurt yourself and others you love. There is reason why chlorine dioxide is not used in swimming pools and it's because of the safety hazards it poses. Yes, it can be used in large commercial pools and water treatment facilities where there are control systems in place for proper handling, injection and monitoring, but that is not your backyard pool.
Chlorine dioxide is a gas, not a solid. The solid stuff is sodium chlorite which you are expected to mix with an acid in order to generate chlorine dioxide gas. This is a very difficult thing to do in a pool and, as I said above, can lead to potential poisoning. People have died messing around with stuff (aka, "Magic Mineral Solution").
If your pool is going to be replastered then you just have to live with the black algae until it is. Do a full chip out of the paster and have the contractor chemically sanitize the concrete shell by doing an acid wash and a bleach wash. High pressure steam can also be used to sanitize concrete surfaces that have algae problems. Then the contractor can apply a new plaster layer.