Just curious why. I've used a garbage disposal the last 10yrs with a septic tank, no issues. There's only me and the misses and we watch what goes in there (usually), plus used the dishwasher.
The material hasn't gone through the first digester (our guts). However, they do make disposers specifically for septic tanks. They've got a separate feature that dispenses enzymes in the waste to jumpstart the process.
The tank fills up faster because the microbes in the septic tank are overwhelmed ..........