It might well have been wet when I wound up doing my accidental brick-making! This was waaaay back when, and I’ve definitely slept since then.But did you work the soil when it was wet?
I agree. Organic material (not certified organic as you said) is a great amendment to any soil, whether heavy clay, mostly sand, or anywhere in between. The best soils to grow things are generally a good mix of clay, sand, and organic material (compost). The clay contains certain minerals that the plants need. The sand helps with drainage. Compost helps with the tilth of clay soils, moisture retention of sandy soils, and provides certain nutrients (like nitrogen) that leach out of the soil over time.
Clayey soils will set up hard as a rock if you work them wet as that affects the charges on the individual clay particles. Adding sand does not affect that charge. I welcome experimentation. Try mixes of clay and sand versus just clay that has been wet and squished to see if one is really harder.