Re: Hijack the hijack?
You wouldn't want to run a Javascript miner, you'd want to get one written in C for greater efficiency, or better yet runs on a discrete GPU if you have one.
With Monero (which is what's being mined in most of these cases) there's very, very little advantage to using a GPU over a CPU - it was specifically designed to limit the advantage.
But, yes, a miner written in C (or in fact, almost any other language) will be more efficient that one running within the browser, even as Web Assembler.