I imagine this is good advice in some places, but as a line manager, if you pull this on me I'm more than likely to shake your hand and wish you luck in your new job.
In a lot of places, having a talk with your manager about your salary before going off and actively looking for other offers is going to go down a lot better. Most line managers worth working for, value their teams and will fight for them if they are unhappy, without the threats.
And TBH, if your company has to make cutbacks in the future and you've shown you're willing to up and leave at the drop of a hat, you're name's likely to get further up the redundancy list than you'd probably like.
In a lot of places, having a talk with your manager about your salary before going off and actively looking for other offers is going to go down a lot better. Most line managers worth working for, value their teams and will fight for them if they are unhappy, without the threats.
And TBH, if your company has to make cutbacks in the future and you've shown you're willing to up and leave at the drop of a hat, you're name's likely to get further up the redundancy list than you'd probably like.