Yes, it should be allright with 1 or 2 volts reverse. That circuit charges the cap backwards to about 1.5 volts. But if you are worried about it, you can use 2 larger caps back to back. Or, you might make it work using a non-polarized 2uF cap and somewhere around 1 meg in place of the 47K.
Here's some data on electrolytic caps.
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-Bill