You can't swallow it. There's a huge difference between holding something in your mouth and swallowing it. Once it goes down your throat you won't feel good. Seriously, I've swallowed some accidentally before and that was a very bad stomach ache.
same reason you shouldn't swallow toothpaste. it's not good for your body to ingest a lot of it (a little left over shouldn't noticeably affect you) but mouthfuls can upset your stomach, strain your liver, and generally mess up your insides. not suggested for getting drunk since it's also poisonous! not extremely but if you have too much it can cause serious damage, just follow the bottle's instructions and you'll be fine