This isn't really alternative medicine. You need to become better acquainted with the hygiene hypothesis:

http://en.wikipedia.org/wiki/Hygiene_hypothesis

We've covered this material in both of the immunology courses at my university. It's a fairly uncontroversial idea nowadays (and it should be that way, given the evidence).

You might have this idea that you're somehow a biologically independent organism from the commensals in your gut and skin, but you're not. Humans (and other animals, of course) evolved symbiotically with their intestinal flora, and are heavily dependent on it for survival.

If still you feel that this is yucky, remember that you have about three pounds of bacteria in your gut (at least in an average healthy human adult), and you need it to live!

This does not mean that we shouldn't find another way of treating people (with a vaccine that stimulates IgE production against worms, for instance). For the moment, however, worms are cheap (and they appear to work). And if you purify your culture properly, they really aren't a bad idea; clinical trials with them are underway for a variety of conditions (MS, for one).

Finally, remember that anti-vaccine nutters often invoke phrases such as "fraught with peril" when railing against vaccines. But consider the peril we would all be in without them!