This pattern is for knit slippers, but I can totally see using a wool sweater and cutting and serging slippers from it! Home Slippers - DIY. this is knitting, but I bet I could use this to crochet some
i think you could make this with tunisian. when it gets the the split, you could keep working half the stitches until both halves are long enough and then start stitching across the entire piece again at the other end.