The mop head is plenty full. Yes, the thing works sort of like a salad spinner.
The mop heads can be removed and washed. I seldom do that, however, since I put some bleach in my "clean water" bucket, and leave the mop to sit in that between uses. The Aldi mop comes with two extra mop heads, and they snap on and off fairly easily.
If you have a floor with any unevenness (such as textured linoleum or tile), this kind of mop does a much better job of getting into the nooks and crevices than any sponge mop I've ever tried. The only thing that can challenge it for cleaning ability is getting down on your hands and knees with a heavy duty rag or scrub brush.
I've used the industrial size rag mops with the big wringer buckets in the past, and have always ended up with an aching back after cleaning a good size room. This does a better job, and no aching back.
It will also pick up a lot of liquid. I have had three old, not-very-continent dogs to clean up after during the last year and a half (two now gone, to my great sorrow), and this has saved me a fortune in paper towels. I mop up, wring out well, rinse in the water-with-bleach, and go over the floor again. I have a mop dedicated to these spot cleanups, and another one that I use for the general floor cleaning.
IOW, my mops have been getting really heavy, constant use. I do spray the gear mechanisms with lubricant every couple of weeks to keep the spinner working smoothly, since the mops get such constant use.
