I just melt a hunk o' TAC#1 in a little condiment cup and dip mine just to the crimp groove with a pair of pliers and set em back on the wax paper and cut em out later.
My cutter was designed to have .002 clearance on each side of a boolit sized to .358, so it is .362 and does leave a small film on the side. To get em slicked up like in the picture above your post, I run em through the Lee sizer again to get that .002 off of em. Buildup isn't a problem in my Lee dies, but I do size em again before using my Hornady Dimension series, because it has a little sliding sleeve in there that holds the boolit in alignment with the case all the way through seating and it will get some buildup on it. I only use the Hornady's on the wife's 125gr .38 loads though. Apparently the Lee lines up the longer case of the .357 and the longer boolit well enough and I don't need that kind of precision for loading them.
So to answer your question.... after casting, I tumble em very very lightly in Alox (the sizer will sometimes put a "skirt" of lead on em if I don't lube em just a little before sizing), then size, dip, cut out, and then sometimes
shove em through the sizer again to clean em up extra pretty or
I can just load after cutting out.