I like the strategy and employ it on a portion of my 401k. I think you need to do it in a tax-advantaged account, otherwise rebalancing + short term gains will eat away your profits.
Also, that strategy fails in a rising interest rates environment like in the 50s and 60s (not sure of exact years). Fed has indicated keeping rates low for the next two years, but if they start hiking rates after, I think the strategy would underperform.