In the washer, the clothes often turn inside out during the agitation cycle. Turning the clothes inside out first may be easier on the clothing. It limits abrasion on the "good" side of the fabric, reducing "pilling" and extending the life of some fabrics such as corduroy. In addition, any embroidery, decals, and so on are better preserved. It should not affect the performance of the cleaning action to have the clothes inside out during wash.