Instead of DM's try tweets. Less people do that.
Ugh - I don't like it when they tweet and @mention . Especially if you only followed in the hope of a follow back.
I should have been clearer though: When I said "worked for me", as in it made me take notice rather than it was a strategy I was using. I might nick similar though - although I think a delayed auto DM would be less spammy looking