I used Qtips loaded with Hoppes 9 or a FP-10 CLP. I usually never neglect my pistol but it there is crud sitting from more then a "few" sessions just let the Hoppes or CLP sit for a few minutes while you clean something else then while it off with a clean patch. You can always use a nylon brush or tooth brush to scrub some of the crud out of the reciever.
Spray down with MPro 7 then brush with toothbrush and while actuating trigger with finger go digging around with Mpro7 moistend Qtips. You could also consider some spray cleaner to blast all the wet crud out after this...I just wipe it dry and relube.