raw wool is SOOOO oily. my mom, who was the best knitter, used to prepare her own wool, already spun, but not processed in any way. she spent days getting it clean in the bathtub, soaking in woolite and then swishing. rinse and repeat. even then, it never felt completely free of oil. i'm not sure i would use unprocessed wool in a quilt batt. the oiliness might wick into the cotton, no matter how much you washed it. that's just my opinion.