My squirrel loads are 30 grs 3f w/ a .445 RB and a .018 patch. ...it's a "clean" shooting load.
Personally, I think a lot of this "stuff" is over thought. After accuracy handloading for a few CF cartridges, this MLing shooting isn't all that complicated.
I don't wipe or swab the bore when on the range or when hunting .....just use a wire brush and dump the debris after the load becomes difficult to ram down. This is usually after 5-10 shots are taken. In Colorado it's closer to 3- 5 shots because of the lower humidity. In Wisconsin w/ it/s higher humidity, the wire brushing frequency is less often..... after5-10 shots.
My elk load in a .54 Hawken that I built is 120 grs 3f w/ a .535 PRB.....no trouble reloading for 3 shots and then the wire brush is used and the next load is easily rammed in. but, this is in Colorado w/ it/s much lower humidity.
There are a lot of products on the market to clean your gun better.....I just use hot water which is next to nothing in cost...have been doing this for many years.
I've found one product that does it all...Wonderlube 1000 Plus by Oxyoke. Patch lube, rust preventative for both the bore and outside surfaces and it's also good for chapped lips.
Don't think there are "hard and fast rules" as to the frequency of using a wire brush...the frequencies stated above are approx. and depend on a number of factors, but the approx. frequencies as stated are what I've found to be "in the ball park"......Fred