All the resources here and accounts of people's actual experiences suggest that the majority of the cases are relatively painless, maybe with a little bit of discomfort. But I'd take this with a grain of salt because everyone's body reacts to things differently. I'd suggest do your own research as suggested in every guide and megathread that you'll find here. Read through some of the journal articles(Try google scholar, it's actually quite easy to find cases related to SN these days) that are available about deaths/near deaths from SN consumption and how it affects the body, and make up your mind with full knowledge of all the risks.