I've been doing initial phone screens (small companies) this week (two just today, actually), and with all of them when the recruiter (internal or external) gets to the "we'd like to send you a coding challenge" I interject with: "Let's do a code exchange. I'll point you at some of my GH projects, and you send me some of your code".
So far they've accepted ("I'll forward it to the hiring manager"), and it's far too soon to see if this works... but I'm hoping.
The next step I'll be trying is "I'd like you to pay me for my time. If you're not comfortable with that yet, let's talk about what's involved in getting there."