How should I use this bar for pre-treating stains on clothing?

For spot treatment, dampen the stained portion of the garment with cool or lukewarm water. Rub the soap bar directly on the stain to deposit a visible layer of lather, working it gently into the fibers with your fingers or a soft brush. Let the lather sit for 5–15 minutes — this gives the soap molecules time to emulsify oils and loosen particulate soils. For older or heavier stains (collar grime, cuff marks, food grease), you can leave it longer, up to 30 minutes, but avoid letting the soap dry completely on the fabric as it may leave a residue that requires extra rinsing. After the dwell time, wash the item by hand or machine as normal. Always test on an inside seam or hidden area first when treating wool, silk, viscose, or any fabric labeled "dry clean only" or "delicate," as the high pH and mechanical action can damage fibers or cause color loss. Rinse thoroughly; any remaining soap can stiffen fabric once dry.