Odds of Getting In
Here's the thing: This is a high paying job that you can learn in two to three years; you don't have to go to med school, and the hours are good—it's kinda cushy, right?
You don't think you're the only one who's discovered this, do you?
There's lots of places to get accredited. There are lots of schools opening up to train dental hygienists, which incidentally is another good gig, but you'll need at least a BS to run a dental hygienist's school.
Recently there were too many new schools opening up, and too many new dental hygienists being created, looking for jobs.
It started to look like a dental hygienist clone army was forming in some places.
In 2013, the ADA started cracking down on new accreditation programs cropping up and had them curtail the number of new hygienist applicants (source). There are still a lot of hygienists out there, but that doesn't mean you won't be able to find a job. It depends on where you live and how saturated your local job market is with dental hygienists. You'll have to do some research on job openings and speak to dentists in your area.