>>11305761Different Anon here, but if you don't mind, I'd like to chime in as well, and share some of what I've learned about this tech over the past year.
If you can be bothered to muck about with Photoshop, or what have you, and use the image2image genning feature with sample images, you can have any level and depth of sinking you want, in any pose you want, even if completely ridiculous for the situation.
See pick related: That started out as a simple stencil of a flesh colored stick figure posing arms up like that, while surrounded by a simple brown blob around her waist that symbolizes the slurry. Then simply prompt with the AI what you want the image to look like, like Anon
>>11305900 has already explained to you.
About prompts: You should also take advantage of negative prompts by listing in the negative all the body parts that you don't want to be visible. This character's navel, ass, pussy, legs and feet cannot be seen, so add them to negative prompts. On the other hand, her boobs, and everything else on the upper torso are visible, so list these in the normal/positive prompts.
If you want a late stage sinking, where only the face can be seen above the quicksand's surface, simply list face, eyes, nose, mouth as the only normal prompts, and add every other body part that is not supposed to be visible, but instead hidden under the mud to negative prompts. And maybe use a paint program to draw a simple image of a flesh colored ball, representing the face, surrounded by a pool of brown color. Then feed that to your AI's img2img generator.
My explanation may have sucked, but hopefully it helps you to create many beautiful quicksand drownings.