I have terrible problems with itchy ears, and my ReSound dot220 doesn't help! But I think it is critical which "dome" they fit on the receiver part that goes in your ears. I'm thinking that maybe my "dome" is too big, and therefore irritates the ear.
My ENT has me use a solution of 1 part rubbing alcohol and 1 part vinegar, a couple drops in the ear. He says the alcohol kills anything that might be growing in there and then evaporates quickly. But the vinegar remains longer, and keeps the ear at the proper pH. This does work a little for me. However, I use a teeny tiny bit of cortisone as well. You have to be really careful about using the cortisone along with the hearing aid, so it doesn't gum things up! This works quite well.
It takes a lot of patience and commitment to make it successfully through the hearing aid process. Good luck!