Many, many years ago, I found someone at a cat show who was selling a special powder for treating ear mites in cats. It was in a sort of small squeeze bottle that had a narrow funnel with a small hole at the tip that you would attach in place of the cap. The powder was blown (sort of puffed) into the cat's ear, so that it probably spread around well, contacting the mites.
Of course, my cats hated having anything blown into their ears, however gently, but it worked beautifully in a short time and was minimally messy. The powder contained 3 ingredients, and I only remember that boric acid was one of them. I wish I remembered the other 2, but in any case, the person that was selling the powder mix didn't say what proportions they were in. I have been searching online in hopes that someone will have posted about something like it.
Boric acid, it's not dangerous I used it for eye wash whenever you get a fungal infection in your eye the reason it works for cockroaches is it dehydrates it's outside skeleton then anything else it will kill it. Just because it has acid in its name it is not dangerous. For instance it could also be used on baby blankets, babies pajamas as it makes it fire retardant. In a new Foster I'm using boric acid and peroxide carefully with an eyedropper to get rid of the infection and then I'm going to be using it oil to break down the wax sand to smother the mites.
It's the peroxide that can blind a cat if too much gets into this it's just like the peroxide washes for contacts if you don't give it to 12 hours to break down it burns your eyes like crazy.
My Cat has suffered with ear mites forever and I have tried everything my local vet has recommended and nothing has worked. So..I recently started using a wash of boric acid & warm water swabed out with cotton ball then a few drops in each ear of sweet oil! Seems to be working so far. However, I discovered through reading everyone eles's posts that I probably should continue treatment for approximately 1 month in order to kill the mites.
I grew up with a lot of ear infections and my grandmother always treated me with a lil boric acid and in no time, I was better. My bestfriend grew up on sweet oil for ear infections; so I figured it couldn't hurt to try it.
I use about a tablespoon of warm water to an 1/4 tsp boric acid; soak a cotton ball and swab out the ear. Then I use an eye dropper and apply 4 or 5 drops of sweet oil to each ear. I usually do this every other day. The washing usually only has to be done once per treatment. Use judgement based on look of ears.