There's not much else goes inside the dry bag, except clothes. The dry bag is then wrapped up and things which don't need to be in it aren't (cooking gear, tent, food etc). This has worked for years including TGO Challenges, a few alpine trips (inc TMB twice) and ML assessment. Sometimes I will put the bag in a large stuff sack (which then doubles as my pillow) but I rarely compress it before putting it in the rucksack.