That extraction reads like it should work. See also
this page from the wiki for a more detailed (and not that complex) procedure. Processing the seeds is
definitely a good idea - I've experimented with hawaiian baby woodrose seeds quite a few time and I've never encountered a taste as foul as those seeds being chewed; it can be enough to induce vomiting by itself.
You should also wash the seeds thoroughly before extracting as if I'm not mistaken they are sometimes coated with fungicides and the like.
As for what to expect from the experience, personally I've found the effects surprisingly powerful although much less visual than with LSD. It also pairs very very well with some cannabis (although I would recommend trying it by itself at least the first time to get a good handle on it/discover it properly).