Q. Is it ok to use OxiClean® Laundry Stain Remover Spray with regular Clorox® Regular-Bleach?

A. For white cotton t-shirts, you can use Clorox® Oxi-Magic before using Clorox® Regular-Bleach in the wash. I assume you are pre-treating with the Clorox® Oxi-Magic. These are two different products and use different bleach chemistry. Clorox® Oxi-Magic is based on hydrogen peroxide which can react with the sodium hypochlorite active in Clorox® Regular-Bleach to create oxygen gas. If you have stains on the t-shirts, I would consider using Clorox® BleachPen 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.