Cleaning schedule.
There is no hard answer for that. It's directly relative to your locale, usage, and frequency of carry. Its just too broad and the phrase "#### happens" holds true. I will say this. ARs, properly set up from quality components, will run with greater ferocity when kept lubed (wet). This has been proven time and time again. That doesn't mean its OK to keep your duty weapon nasty, you have to cover your ass at the same time.
Just file "it will run wet" away as a continuing action. That means keeping the gun up and running while shooting. Not so much for a LE shooter, because extended gunfights are an extreme rarity.
Cleaning Steps.
This is what I do, and what I tell my shooters to focus on.
Bolt, Bore, and Chamber Mod 1 (Priority of Maintenance)
This is a bit different from what I was taught in the Corps, as I've learn some #### about guns since T1 at MCRD. At no time do you need to use anything harder on your weapon than a wooden Qtip stick or nylon brush. You aren't cleaning to remove the finish. You clean to remove the fouling and gunk.
The Mod 1 I am referring to is just the application of uncommon sense. You clean the weapon in the direction of bullet travel. Therefore that means it would make more uncommon sense to prep the bore with a wet patch (solvent) and let it sit as you proceed with cleaning.
Keep in mind, as you clean you should be visually inspecting the weapon and its components for possible signs of trouble. That's fractures, cracks, wear (not shiny places) resulting in a raised burr, or a broken part. You'll know if its broken if it buzzes when you tap it (pistol frame rail) or if its a jagged place with a light crystalline gray appearance where a locking lug used to be.
As you visually inspect the weapon, look for symmetry.
-Do the hammer spring legs on either side of the hammer and trigger, mirror each other? Does the hammer swing true? Or is it canted or not parallel in the receiver?
-Is the gas tube parallel with the charging handle raceway?
-Does the carrier slide forward easily without any noticeable wiggle of the gas tube (without bolt installed of course).
-Is there only one lug on one side of the extractor?
-Does the Firing Pin Retaining Pin look like hammered ####?
-Are my sights canted?
....that kinda ####.
Cleaning your bolt:
Remove the extractor and clean the extractor recess. I do this after I've suspended the bolt in a jar of Slip Carbon Killer for 10 or 15 minutes. Means little scrubbing. While the bolt is soaking I clean the interior of the upper/chamber with Carbon Killer, chamber brush if needed, and Qtips/Rags. Change patches, QTips, and Rags as often as they get dirty. You don't wipe your ass with the same #### ticket over and over do you?
I do not waste time on the tail of the bolt, if it doesn't wipe off, it stays. Don't pick at the gas rings. Just wipe any #### off of them so that you can insure that they aren't missing or broken and bent.
I do get that firing pin channel clean by pipe cleaner and Slip, then blast it out with air.
While I'm cleaning that bolt I soak the carrier in the Carbon Killer. Blast it out with air, then lightly brush and wipe the thing down. Same goes for the firing pin, extractor and cam pin. Be sure to get the Cam Pin raceway clean, as carbon there can cause drag. Again, carbon there wont shut a gun down as long as it's lubed.
Once you are done with the bolt and carrier, reassemble it. ( don't leave the parts sitting around so that you can lose them.) Check your gas rings by setting the bolt carrier vertically on the bolt face. It should not fall closed under its own weight. If it doesn't, then bump the table, it should fall part way but not completely foreward. If it does, you need new gas rings.
Now that your bolt carrier assy, and chamber are clean, you go to the bore.
DO NOT HARPOON THE CHAMBER WITH YOUR BOREBRUSH or EYELET. It is not designed to work that way. You feed the rod from the chamber end, while pulling the brush/patch through the bore. When done this way it is a one person job. If you harpoon it, you will bend ####, break the rod, or get the whole thing stuck as the brush bends, or your patch wraps the eyelet and causes a restriction. Pull the brush a couple passes, then go to the patches. Use a patch only once. Again, #### tickets and your ass.
Do not fist the bore like your favorite Ex. There is no need to scrub the bore back and forth with the bore brush.
Lastly, Lube and reassemble the weapon. Perform a functions check to insure it is assembled correctly.
Oh, once all this is done. Now you can worry about getting the dust and rust off of the externals of the weapon. Once done, do some mag drills and snap in. This will let you know if your mags, mag release, sights, and optics are GTG.
BOLT BORE AND CHAMBER
PREP-BORE, BOLT, CHAMBER, CLEAN BORE
Once that's done, worry about cleaning the buffer assy and lower internals. That can be achieved with flushing it with some solvent, fresh water rinse, blast it dry, and some lube.