I have also thought of this strategy.
However, recently I tried to sell all but 1 share of a holding and my online broker would not let me proceed with the trade because it would leave me with an unmarketable parcel. Not sure if every broker uses this rule.
Also discovered that my broker would sell an old unmarketable parcel for me at no cost, ie they kept the $12 or whatever from the sale and didn't charge me anything.
