Whenever I import names, I drop them through TextPad (
http://www.textpad.com/) first. I use this method to quickly remove domains I don't want (i.e., numeric, hyphen, ccTLDsm, etc):
To remove stuff you don't want...
1. Press F5 (search), type the search phrase you DON'T want. Click Mark All. (Tip: You can use regex, if you know it. For instance, to remove numbers, enter "[0-9]" (without the quotes) and make sure the Regular Expression box is checked.
2. Click Edit >> Delete >> Bookmarked Lines
To show just the stuff you do want...
1. Press F5 (search), type the search phrase you DO want (i.e., ".com"). Click Mark All.
2. Select All (CTRL-A)
3. Click Search >> Toggle Bookmark (or CTRL-F2)
4. Click Edit >> Delete >> Bookmarked Lines
Hope this helps.