For .45 Colt in Starline cases, I use 21grn of FFFg, a Circle Fly .450 prelubed wad and 230gr RN cast bullets usually designed for .45 ACP and put a heavy crimp on them with a Lee factory crimp die. I get good, full combustion with little fouling, and it shoots much harder than most "cowboy" loads and hit point of aim at 20 yards from a 6" S&W HE that was once .455 Webley but converted. The wads are the only way to use a reduced load in a case- all the room in the case must be filled with powder, wad (or filler) or bullet and put a slight (about 10%) compression on the powder for a good, full burn.
A compression die is not needed in pistol sized cartridges, although some people do use them on pistol cartridges.
The other thing is, depending upon the case and bullet, the charge will change because the case must always be full. I had to experiment with my powder charge until I found the right charge that filled the case with good compression allowed the bullet to crimp in the correct position that I needed.
The wads from Circle Fly are very thick, and have had no leading whatsoever- I'm certain it allows little gas past it to the base of the bullet. It's much less trouble than using cream of wheat/grits- unless you have another powder measure set up to throw the right amount of the buffer material.
The one thing about loading cartridges, a powder thrower (measure) for black powder will prove to be very valuable if you start to reload many cartridges. Measuring charges with the same measure you use for muzzle loading rifles one at a time is time consuming and monotonous. I did it for a while on brass shells until I got a Hornady measure- which was one of my best investments.
As for cleaning cases, I use stainless steel media in a Thumler's tumbler and some lemi-shine and dawn- no matter how bad the brass is, it will come clean and polished. Just one thing- never put two different calibers of brass in a tumbler...it never turns out well.