I use them in wines, especially blackberry and grape. My thought is that oak imparts a strong flavor that I don't know would be appealing in cider. You could take a 1/4 cup of your cider and put it over some oak and try it before doing the whole batch.
Yea i did on my first batch. I used a cup of chips that were soaked for twelve hours before adding to the carboy. then i kept them in the cider for two week before i bottled. i opened a bottle a week after bottling and it had a strong oak flavor. after another two weeks i opened a bottle and the strong oak favor had smoothed out and the cider has a great flavor.
I soaked the chips in water with a paper towel covering the glass. You could also soak the chips in a glass of Bourbon or whiskey. The alcohol would kill anything nasty that might be living in the chips. That is if the cider has a low alcohol content. Like 7% or less. If it is higher than that you should be fine with soaking them in water. The alcohol that is in the cider should kill any thing that might be living in the chips.
Hoped that helps.