significance of the quote the thing is you can scrub walter cunningham till he shines you can put hhim in shoes aand anew suit but he willnever be like jem. besides there is drinking in that family. finch women arenot interested in that sort of people

Aunt Alexandra is being just a bit uppity here..... proving that even the "missionary" women indulge in class distinction. She's telling Scout that the two shouldn't be spending time together, and that Walter will never be as good as they are...... it's that old "you can dress them up, but you can't take them out," mentality.