I haven’t tried the photo trick (mainly through a good magnifying glass) – so I’ll try that.
But I have gone between the tracks multiple times with a small flathead screwdriver, then a small kitchen knife, and then actually even a small hobby hacksaw that had a long straight blade. I also reflowed all the joints multiple times (which then necessitated going back over the tracks each time with a blade just to be safe – it’s a never-ending cycle

).