We give candidates all the time they need, as in a week or more. We explain the process when we ask them to interview, and if they prefer a white board interview instead of a take home, we can do that. So far, no one has taken that option.
You're right that some people object to being asked to do programming (though none that we've asked to come in have objected) and some people think they should be compensated, which we don't do. I point out that the code review, for example, takes my team of 4-5 engineers 1-2 hours of their time, so we are matching the candidate's time spent with my team's time.
In any case, it's certainly not for everyone, and we're flexible.
The standard whiteboard hazing trivia is bad enough, and 4+ hour long marathon on-sites that require weeks of study and taking vacation days just to interview are ridiculous. But your method is not much better. You’re still perpetuating this myth that somehow, unlike virtually every other profession on the planet, software engineering requires intense examination of on-the-spot demonstrated skill, rather than simple conversation probing past experience and domain knowledge.
We just do interviewing completely ass backwards in software. Part to assert gatekeeper superiority, part to judge fealty. It’s just bananas.
BTW, I will consider the approach of simple conversation probing past experience and domain knowledge. I infer that would be in lieu of a coding demonstration. If that has worked for you, any detail that you can fill in would be appreciated.