i've had good success with the 50/50 hoppes#9 and marvel mystery oil for a few years. i also at times mix Rislone engine treatment with #9. it makes a cleaner with greater lubricity than does the marvel mystery oil mix. Rislone put on a patch will clean a bore of the powder fouling and allows it to stay anointed for a couple days without rust settling in.
i recently put some Rislone on a shop towel, cleaned the exterior of the brass with it, put some rislone and synthetic oil on a mop to clean/lube the inside neck, wiped the outside of the brass with a little synthetic oil and got Great results re-sizing the brass. i washed it all of with hot water and Ajax Lemon dish soap. but the water needs to be HOT.
take care,
ss'
ps: for a cheap case lube i've been using 5w-30 or 10w-30 synthetic motor oil for several years........with no problems.