Something like STP oil treatment (is that still around?) would stay on the cam like glue. That stuff is STICKY. I've used it as transmission lube in a Model A tranny. But it's not good in cold weather. When it got to freezing temps, I just about bent the shift lever.
What if the problem is not about the lubricant?
There's a rubbing block in the grease cup that's there to keep the distributor shaft pushed against one side of the bushing (to keep the point gap constant for each cylinder). That might be dry and only causing problems when the rubbing block for the points is pushing against the cam. It's a possibility. You might check that, and put some grease in the cup.
