It sounds incredible, but the effect of my new orthotics was practically instantaneous. I'm not counting Wednesday after I picked them up, because my heel was already getting sore by that time.
However, yesterday and today I've worn them without any significant discomfort. There is some low-level throbbing, but it's almost not enough to stand out against background radiation. And I don't seem to have trouble getting used to them. I was warned it takes three weeks for your feet to get used to them and advised to start by wearing them an hour a day. I did, but after that hour they weren't bothering me and I just kept them in.
In fact, I didn't like not wearing them at night (I've been wearing spa slippers recently) enough to find my trusty fluffy camel slippers, because they are stiff enough and fit closely enough to be able to wear the inlays.