Once again we're divided by a common language, and regional variances don't make it easier.
I like to agree with someone who lives close to the thing I'm trying to pronounce. In this case, let's go with Jock.
Here's an example from where I live. The eastern side of the U.S. is home to a range of mountains spelled Appalachia. The right way to say it is to keep the 1st and 3rd "a" short, as in "apple", and the 2nd and 4th sound like "uh", as in "ugly", with the heavy stress falling on the "-lach" part of the word. However, people who don't live around here or who try to appear "educated" say it "AppaLAYchia", which stands out like a sore thumb. Folks from other places often try to correct those of us who live here, because they've heard it said that way on television. I suppose this sort of thing happens all over the world, especially in French-speaking places, because of the different vowel combinations and silent consonants.