Hi Steve, I would be concerned about the sugar as stuff in the coke gumming it up some more. About the best penetration oil I've found is PB Blaster, available at any parts store. Also, automotive brake cleaner will blow out and clean up a lot of junk. A plus here is that is leaves no residue.
You could always try diet coke...
I'm not slow, I'm pacing myself!
Isaiah 44:13 Another shapes wood, he extends a measuring line, he outlines it with red chalk. He works it with planes and outlines it with a compass...
Usual kit: Table saw, band saw, dual base router and table, lathe, various saws, planer, sanders, and a multitude of hand tools.