ccurtis - Good points and something I had not considered. The glitches are on the outputs that drive the fets - if they glitch at the wrong time, current will flow direct from power to ground, wasting precious battery power. Sinusoidal power is a possibility... I put a filter on the fet inputs and use them like an amplifier rather than a switch. It will require adding four components, but it might just work a treat.
Ron - another excellent point, and a consequence of making last minute changes to circuit diagrams that then don't reflect what you're actually doing. In the real circuit there is a gate between the clock and the filter - in my haste to produce a jpg to post I forgot to include it. Mea culpa.
I've attached the corrected circuit, now fortified with extra correctness.