Drilling coral branches

I am trying to drill long [2 inch] pink coral branches. I ordered
diamond needles drill bits jade punch needles used to drill jade, from China. They are long drill bits with channels to get rid of gunk from inside the coral. In the past I have drilled into coral and found it quite soft, now I’m making no progress. I’m trying to drill lengthwise. Can anyone help? Thanks, Christina

HI, a ultrasonic drill is a good investment. $1,000+