Greasing control arm shafts

[Fred T]

I discovered today that when my son greased my new front end, he didn't get grease through the lower control arm shafts. I was able to get one side greased by blocking the frame and working the control arm up and down with a jack, but I couldn't get grease through the shaft on the other side. I had enough pressure that grease was oozing out of the joints on the filler tube, but it wouldn't go through the shaft.

My thought is to back the shaft nut almost off, then pump grease in and screw the nut back down, hoping this would push the grease through the threads on the shaft.