Licking the floor!

Detoxify - yes but why does the stiffness come back so fast, Why does it go away so abruptly?

This immediacy of the effect is a bit similar to the effect of long exhalations. More time on the exhale and less time on the inhale mean less oxygen in blood but more in the tissues (Bohr effect).
I can feel my muscles relax in a minute if I do Pranayama that way; and that goes away as fast when I start breathing normally.

Something to do with deep tissue oxygenation maybe?
Or something else?

Congratulations on your newfound ability to lick the floor :-)
It's good to feel like a kid in your own body!
Iodine = Playfulness!