Itchy Ears

I'm afraid that my rabbits may have ear mites.  I've seen some pretty graphic pictures online showing what ear mites can do, but when I look in their ears, they appear to be clean.  I've posted some pictures below.  You can't see into the canal in these photos, but I don't really see much when I look inside their ears.  The doe's ears seem slightly worse than the buck's, but he's easier to deal with so I took photos of him.  Her outer ears are just as clean looking as his are, but her ear canals look a little dirty when I look deep down.  They are not shaking their heads, but do scratch their ears fairly regularly.  I want to be proactive on this rather than wait and see.  In the book, Barnyard in your Backyard, they recommend:

1. Miticide-containing oil or olive, cooking, or mineral oil in the rabbit's ear.  Put drops in the ear and massage gently to distribute the oil.
2.  Cotton swaps to remove loose crusty matter.
3.  Repeat for 3 days, wait for 10, then repeat for 3 more days.

They also suggest Ivermectin (either injected or swabbed into ears).  Big Country (Leo), however, doesn't recommend using Ivermectin without veterinarian supervision.  He used baby oil to successfully treat his rabbits.  Barbi Brown's Bunnies recommends using mineral oil in a spray bottle. 

Has anyone had experience treating ear mites.  If so, what do you suggest to treat them or to prevent them?  I prefer the mineral oil route rather than the Ivermectin or miticide, but whatever I use I want it to work the first time rather than making it worse.