I would not mist with softened water. It has too much sodium, which may get into the soil in the pots. Your outdoor faucet shouldn't have softened water (kills gardens), so I would hook a timer up to the outdoor faucet and then hook the misters right to that. What I do to prevent my misters from getting clogged is to use a descaler. It keeps them from getting plugged and doesnt use salt. The descaler I use is an in-line kind, like used in the line before water heaters. You could put it between the faucet and timer. Or just clean the nozzles regularly with a needle...
Carolyn