Been there. I did a rough test last summer on a two week trip, packed the same clothes in cubes one way and rolled loose the other, and loose won by a solid 2 to 3 liters in my 40L. The trick with rolling is you fill every corner and squash soft stuff into gaps, while cube walls leave dead space at the edges of the bag. That said, my wife still uses cubes and refuses to switch because she can find things without unpacking everything, which honestly saves her time even if it costs a little room. So it depends on whether you care more about squeezing out space or staying sane digging through your bag.

The "spray bottle of distilled water with a soft sponge" tip is real and my buddy swears by it too. He digs out near Florence and had a plain brown sherd that looked like nothing, then he misted it and a whole black-on-white design showed up. But he tried the same thing on a chunk of burned bone from a site and it went soft and crumbly on him, like the water just ate it. Shell is even worse from what he told me, the water pulls out salts or something and it starts flaking apart. So water is great for pottery and iffy for everything else, best to test a tiny spot first lol.