Quick, don't really agree on the snake oil part and I wouldn't use wd40 in a nitro engine normally. But I meant for it to be used to wash out the acetone and would assume the engine would be run within a few days so it would be fine. After run oil or your suggestions are much better for normal use and longer term storage.

Curious if you've tried ATF in a gummed up engine. It might not work as fast as acetone but considering the detergents in it ATF might work well in dissolving old gummy nitro fuel.