I'm not sure if you're suggesting interviewing and then using the offer to go to your boss and ask for a raise, or if you're suggesting actually changing job, but at a company that really doesn't understand the value of retaining staff going to your boss with an offer that's 30% more than you're on now is going to mean you end up changing job. Few companies are willing to match that sort of increase. They'll let you go and try to find a replacement.

This is the danger of using an offer to try to force your boss to give you a raise - a lot of bosses don't really understand the value you bring, so they'll say no.

That's not a particularly big loss - you still get a 30% raise by changing role, but if you really like your job you should be aware of the risk.