1) Let it soak. These guys soaked for around 2 days & yes that stuff can double for a tyranid digestive pool. If the paint is extra thick it may take a bit longer. More on that later.
2) Scrub, scrub, scrub. The firmer the toothbrush the better. You may need to put some serious pressure behind that brush to get the paint off. For infantry sized models I like to support them by cupping them in my hand while I scrub. Don't be surprised if parts start breaking off. The Simple Green seems to weaken the glue a bit.
3) Wash and repeat. Here is what he looked like after a few minutes of scrubbing. There looks like there is a lot more paint on it then there really is. Once they dried, most of the black turned to grey.
Here are a few all dried off after a good scrubbing.
**For models with really thick paint, you may need to soak them more than once. This model has been primed white, primed black, then painted Vomit Brown. It was a serious mess. I let it soak for a week and started scrubbing. It wasn't making much of a dent so I threw it back in and forgot about it. A few months later I got it back out and scrubbed some more. The paint was coming off really well, but I think it needs one more bath in simple green to really get it good and stripped.
