Can you take better pictures of them, Spike?

Sorry cant right know just asking can I save very dehydrated cacti

I think it depends on how badly dehydrated they are. From this picture, they don't look too bad. I'd be able to help you more with a better picture. If they are brown, shriveled, and dead- obviously not, but these are still green and still have life to them, so I still take a stab at it and say if they still have healthy roots then yes, you can revive them.

Here's the most dehydrated

It's hard for me to tell in that picture as well, sorry.

Doesn't look that bad to me,from what i can see.I've had some that look worse than that and they sent up blooms,so they were'nt dead.I'd try to save them.
Kathi