Becky - any oil/butter will remove the slug slime from human skin, dog fur, hair..... Apply, let it sit for a few moments & scrape. (This works for pine-pitch, too.)
Worms consume organic matter in a decomposing state, and will stick around if they have access to worm-size food particles. If you provide, they will come.
I don't remember having issues with my worms dying from lack of sustenance in either my compost piles or worm bins at any time of the year. Obviously with winter chill, they move to the warmest place for them, usually the middle of the pile. I experimented one summer & fall, placing spent coffee grounds or a pile of weeds in different locations on my property -- worms would typically show up within a day or so. I tried replicating this in makeshift worm bins (large trash cans with holes punched in the bottom), and it worked well. They like small particle food waste with a preference for the coffee grounds. (Perhaps this is typical of Seattle area worms...)
We don't have the extreme temperatures to deal with in this area, so the mortality rate may be different, too. My worm bins were outside & covered to prevent thievery from the marauding local rodentia; the compost piles were in semi-sheltered areas, but open from above. The piles never looked like they'd been disturbed, though.
FYI: Frogs, garter snakes and ducks eat slugs; the ducks doing so with a zealous gluttony.
Maybe I should consider getting a few pet ducks! 
