Yeah it’ll totally work, you might want to mix something in there that’s a binder of some sort but soil blocking is awesome, very low-cost and low-impact way to seed start for small farms, I have a bunch of friends who have those little blocker presses to make cubes with, here’s the explanation from the OGest source, Eliot Coleman whose books I love.
Coleman is a great dude from Maine, super awesome at finding that balance between the traditional and innovative, biology and technology and the human place as mediator between those sometimes. I like that he respects human agency as toolmakers and shapers of our environment while also respecting the power of the natural world and our small place in it. Neat guy!