I've used a drop of Edwal no scratch to wet mount a negative, works perfectly and a quick rinse off with Ronsonol lighter fluid leaves it clean and dry. Kami fluid is a heavier naptha than Ronsonol mixed with mineral spirits. No Scratch is mostly turpentine, so a mix of turps and a bit of ronsonol will work, so will straight mineral spirits. None will harm a negative and no scrubbing required to clean them afterwards. A quick google for msds sheets will give you the cas numbers and proportions.