I don't think they're designed to inject oil onto the push rods. I think most of the oiling is splash fed from the oil supplied by the spray bars. On mine it seemed to drop onto the rocker arms more than anything else.
We've used them since August 2000, We used to do about 120 passes a year 'til 2006, probably getting on for a 900 passes and we haven't had a problem yet with smoked pushrods. Plus we've restricted them more than when they came from Indy. Lucky? maybe