They may be looking to get out, but you are essentially asking them to leave their current job so they can spend a month (or whatever) on a paid interview at your company. You are not only giving up your previous job, you are essentially giving up your ability to interview elsewhere as well. If this doesn't work out, either because you don't like me, or I don't like you, your business, the tech stack, whatever, I am now in a really shitty position, I am giving up what little leverage an employee has in the labor market- the ability to look for a job and say no without worrying about paying his bills.

If you are doing well at a company, I am not sure how you make this seem like a good value proposition, especially in this tech job market. Another way to put it, with a personal spin- I don't work at an actual FANG, but a company that arguably pays better, and their would have to be a very large upside at the other end of this process to make it worth going through. Things would have to be very bad for me to give me up my deep in the six figure job to spend a month interviewing at some place unless it had some legendary track record.

This is all theoretical though and not really worth arguing over. I'd like to see OP try this out and report back the results, good or bad. I could be wrong, but I would be willing to wager that you get a lot more resumes just out of a bootcamp as opposed to people with proven track records currently at prestigious companies.