drysuit leaks

Hi, I conducted a drysuit leak test on my DUI Yukon II drysuit. I did the test with the drysuit right-side out and filled via the drysuit inflator. I clipped the dry gloves on. I sealed the neck with a small plastic bucket and reinforced with electrical Tape. I closed the dump valve completely...

I'm conducting soapy-water leak tests on my old drysuit. Any suggestions on how to mark the leak points once they're found? So far I've tried red and black sharpie markers, white-out, and memory. None are working very well.