Simply run a bronze or nylon brush through the bore and charge holes, one in & out pass will be sufficient. Then wipe down the exterior with your choice of oils and you are done. Might take as long as 1-2 minutes!

BTW, you only have to soften the parafin slightly using heat until it is easy to cut with the cartridge case. Insert the "bullet" first, then prime the case, otherwise air will be trapped in the case and push the bullet right out. You can lay the parafin blocks in the sun or turn your oven on "warm" for a few minutes. Be careful, parafin melts around 150 degrees.

The Speer "Target .38" option is a good one too.