mr-rodin, one computer aid that is very useful for puzzles such as this one is the program, TEA , by Bryson Ltd. It was designed by a former editor of the Listener, Ross Beresford. The company seems to have disappeared from the web, or perhaps it's url has changed, but I think it's still possible to download TEA from other sources.
It's a very fast and versatile program. For instance, in addition to the usual partial word searches and anagram solving, it'll return SUSURRUS from the following entry: 12123321, where the digits indicate the letter pattern. Very useful for getting 4dn and 5dn from the unencoded crossing answers.