Looks like pseudoscience to me.
The Spelling Police have ruled that sulfur is now supposed to be the correct spelling.
I am intrigued that this MSM stuff is odourless; most substances with sulphur in them, especially a sulphydryl (SH) group pong big time! Think H2S or the mercaptans, smelliest substances known!
Various sulphydryl donors are used to protect the liver in cases of paracetamol (acetaminophen) poisoning.