I mean, I get where you’re coming from. But if you’re looking at this from a topological standpoint, I can only point you towards the Vsauce video:
In which case we’re well within the realm of assumptions, because it really depends on perspective how many holes we have.
I prefer the bone interpretation, at least for limbs, because inside out doesn’t necessarily imply the “action of turning inside out” is necessary. So we can just have the straw swap inner and outer positions. That’s how I’d see it, meaning… Bone.
Best link is to look up the Reddit page to find their links in the info bar. We shouldn’t be posting links here, or we might very well lose the privilege once Google catches on…