Does a raffle like this really work?

I'm not sure what you mean by the above. I ran the this raffle or a similar one to it for awhile now. It always gets a decent amount of entries and the winner always gets paid. I'm not sure if that answers your question or not.

I'm checking out a few engagement ideas myself, but don't know what would be the most interesting and organic.

It seems as contest and giveaway posts get the most engagement in them. A well put together top that is discussing the current hot topics on chain seem to do well also.

Feel free to Link me a post once you're done creating your engagement post.