I'm kinda new to the flax diet, but here's what I found out. I'm sure someone more familiar with it than me will be able to also help out. Yoghurt can also be used but if it's for fighting those nasty cancer cells, then no, it's not as efficient as cottage cheese, so you have to have a larger dose. Just what that is, I have no idea. Don't know what sort you should use either (did say I was new to it), but as a personal thing, I'd go low fat so long as it's not filled with other nasties.
But hey, good luck, Cheers, Baggy.