I definitely agree with use it up, wear it out. I've always saved batting remnants that were at least 5 inches wide and had some length -- often join these for placemats and cozies for my Coke and tea glasses. And I join larger pieces with the batting join tape AND a serpentine stitch on my machine.
But, we all need to realize that what we mistakenly think of as cottonseeds in antique battings is actually debris from cotton hulls. Cotton seeds themselves are hard and about the size of a small pea -- unlikely to be missed by those carding their own batts "way back when". Debris is also found in some modern cotton batting because the crushed pieces are so small. Just FYI....
Jan in VA