To recommend inverse funds for the average Joe is irresponsible, but I think most people can see from what they read from you that you are full of it. Inverse funds are not available in 401k funds, anyone who knows anything at all knows that. 401k funds specifically try to discourage short term trading, and if you were in the busines you would be aware of that.
Inverse funds & ETF’s ARE available to IRA’s & Roth’s. They may be available in your 401k also, dependent on your plans offerings…
Also, the advice you gave on holding an index fund as a core of a 401k portfolio, along with bonds, is sound advice for most investors, as these retirement funds are long-term investments. I would add that a larger percentage of stocks (US & foreign) should be allocated for those not nearing retirement (ie higher risk and volatility in the short term for better long term results over bonds).
A strong argument can be made that the economy and equity markets are headed down, and that serious fundamental problems could cause equities to underperform for years, this may very well be the case, though market timing is harder than it looks…
For those that choose to time the market, and understand the risks associated with it, I think an inverse fund is appropriate (though a 2x fund is a bit much unless you have thoroughly defined your risk and understand the pitfalls of leverage, especially when short the market), otherwise, going into cash or bonds during periods of uncertainty may be better for the average joe, since timing errors result in lesser gains (spread between yield and index return) vs. actual losses (which are “compounded” by the additional underperformance to the index).