People really need to stop perpetuating the the belief that capsules will prevent vomiting. I have yet to see any concrete facts backing this up.
The first times I ever saw people on here decide to try capsules were doing it so they wouldn't have to taste the SN drink. It was not to avoid vomiting.
You aren't vomiting because it's gross. It's because you have ingested poison. So regardless of how you get it into your system, your body will try to vomit it back out.
Some people manage to not throw up, but it's not a guarantee and you shouldn't bet on it. It's luck, not method.
Your best shot at preventing vomiting is the correct antiemetics taken properly.