Went to Chivenor for camp in '69 and we were told some of the Hunter pilots were trained on the Sea Vixen specially for this op.
Don't think so. I was on 1(F)Sqn at the time; both 1 and 54 were involved, dropping napalm. I have no knowledge of any cross-training to the Vixen. The timescale was too short for that, only a few days start to finish. Not sure what the Chivenor sqns did, if anything. I think the 1 & 54 aircraft refuelled at Chivenor after their attacks, to fly back to base.
The Vixens from Yeovilton dropped HE bombs. The theory was that the HE would break open the ship, and the napalm would set the oil on fire. It did not work as expected, and, despite the huge columns of smoke, only relatively small amounts of oil were burned.