The thing this article didn't mention and the author likely doesn't know is that there's a guide going around instructing people on how to apply for H1B jobs on forums like 4chan.
This is unlikely to be of use to your friends. Companies hide these job openings because they aren't real: they are filled by a real person right now. If someone applies, they won't be hired because there's no extra headcount. They will just be rejected after a resume review. Companies usually don't even extend interviews to such candidates. Applying only delays the green card process of a foreigner since they will need to rewrite a job description to be even more tailored to that already employed person.