An “expert in removing stubborn grease and stains” would typically be someone who possesses extensive knowledge and skills in using various cleaning methods and products to tackle tough grease and stain removal challenges, often relying on techniques like applying dish soap directly to the stain, blotting excess grease, using baking soda as an absorbent, pre-treating with enzyme cleaners, and utilizing warm water for effective penetration depending on the surface and stain type.