Is the "vacuum pose" possibly unhealthy?

If you know what the ab exercise called the vacuum pose is, can you tell me if it may be dangerous? Supposedly it is a good deep core muscle exercise, and it trims the waistline. I am active so I'm not looking to lose weight, but I want to tone my abs. It seems like a new thing and I've never heard any of my past sports coaches mention it, so I'm a bit cynical about it. I tried it a few days ago, and I felt that same burn that you want while working any muscle, but still- wouldn't "sucking in" like that possibly put strain on your internal organs and have more harm than benefit? Is it a beneficial exercise or a potentially harmful myth? Thanks!