I agree with Mike, a drop or two is enough for atty cleaning. I also use Lemi Shine (Original) powder along with the soap, it helps cut the crud better, 1/4 teaspoon is all that's needed. I got it at WalMart a couple years ago, a bottle will last me years, it's in with the dish washer soaps. It's the same mix I use when cleaning my fired pistol and rifle brass or about any metal objects. I run a batch with the mix, then rinse the parts, then run it again with clean water. https://www.amazon.com/Lemi-Shine-Detergent-Booster-12/dp/B01LW8K6ZG
ETA: I never used TSP in the UC but I bet it would work well, gonna have to give it a try.