Inside out is not really necessery for finding a leak. Only problem could be to locate the leak inside when marked outside. But in almost all cases, it just shows as a small rupture.
If you have an approximate location of the leak, try with a strong strobe first. Close the zipper of your drysuit, look for a very dark environment, put a strong strobe inside the suit via the neck seal. Even small leaks will show up this way. Scan the inside with the light. Only when that doesn't work, I will use water. But I almost always find it with a strobe.
Oh, and if you use transparant glue like Aquasure, your leak will pop up every time you use the strobe technique. The knees of my suit looked like the Milky Way. I'm a videographer in murky oysterland.