Calcium chloride: pushing vs dripping

I am a paramedic instructor and a student asked me if there was a reason that calcium chloride has to be pushed slowly versus diluting it in saline and dripping it in. We carry 1G/10ml preloads. His thought was to dilute that in 100ml NS and drip it in over 5 minutes, versus sitting there and pushing it over 5 minutes. My theory was that diluting it makes it too dilute to be effective, but i otherwise didn't know. I asked one of the ER doctors and he didn't know why it's a slow push versus a drip, and I should ask a pharmacist. Anyone have answers?