Is it ok to use OxiClean® Laundry Stain Remover Spray with regular CClorox® Regular-Bleach₂ with CLOROMAX®?
For white cotton t-shirts, you can use Clorox® Oxi Magic Powder before using Clorox® Regular-Bleach₂ with CLOROMAX® in the wash. I assume you are pre-treating with the Clorox® Oxi Magic Powder. These are two different products and use different bleach chemistry. Clorox® Oxi Magic Powder is based on hydrogen peroxide which can react with the sodium hypochlorite active in Clorox® Regular-Bleach₂ with CLOROMAX® to create oxygen gas. If you have stains on the t-shirts, I would consider using Clorox® Bleach Pen Gel (apply; rub in with scrubber tip; wait 3–5 minutes) before adding to the washer. These products use the same chemistry/active so you won’t reduce the liquid bleach efficacy by using the hydrogen peroxide product.