I didn't ever notice the difference in the number of grooves inside the spike, but makes sense.
I stopped soaking atty heads in Vodka due to some rumours of the Vodka damagind the wick. They could be wrong though..
Cy
I don't know if it damages the wick but I find that if I clean my ego - c type A atty I used during the day each night in simple water, I can keep them running well and tasting great for a long time. Vodka is fairly benign but it scares me when people talk of using rubbing alcohol, toluene, acetone, etc to clean attys.