If they're plugged up with calcium salts, you can soak them in vinegar. I've
eliminated that problem by installing a misting system from Charlie's
Greenhouse, which has a very fine filter before the heads, and a minute
filter within each head, and has never required cleaning in two years.
Hope this helps.
Tom

From: Gideon Singer
Organization: Shaw Residential Internet
Newsgroups: rec.gardens.orchids
Date: Mon, 28 Apr 2003 22:15:17 GMT
Subject: How to unclog mister head?

Anyone have a good way to unclog mister heads?