If you are reading this post I assume that you are an average shooter who does not have access to a parts washer to help you clean your guns. If you want to get the fouling out of your trigger mechanisms without total disassembly you have a few options to help you get the job done.
One is Powder Blast from the Break Free line of products. This a good product that works well and quickly dries on your parts without much residue. It smells like oranges and is not flammable. Another plus is that it doesn’t require a lot of ventilation because the fumes are not that bad.
Gun Scrubber, from Birchwood-Casey, is another product that is similar to Powder Blast. It uses a “jet” action to remove fouling from hard to access areas on your gun. Like Powder Blast, it is non-flammable, but, it cautions about harmful fumes and encourages you to use the product outside or in a well-ventilated areas. While most of these warnings are normally there for legal protection, this is for real. This product is extremely strong.
Both of these products work great, but if you don’t have access to excellent ventilation, go with the Break Free product. All things being equal, it is easier to work with in your home.