All the guns I used to have, prior to that tragic boating accident while ice fishing last winter, I cleaned with M-Pro 7. Then I flush/rinsed with Birchwood Casey Gunscrubber. It removed all traces of the cleaner. Sort of like how brake cleaner works. Most of the guns, except for the M4s, were then lightly and thoroughly oiled with CLP.
The M4s were cleaned, flushed, and lightly and thoroughly oiled throughout, as with all the others, except for the bolt and carrier groups. The BCGs were submerged and soaked, at least overnight, in a container of Mobil 1. When reinstalled in the upper receivers, the BCGs were only wiped off with bare (not bear) hands enough to not be dripping wet. However they were still far wetter than normal for any other firearm. For me, this prevented carbon caking on the bolt and facilitated easier cleaning after extended periods without cleaning.