Cheaper may be to use a diluted solution of Downey to apply lightly to the carpet (a spray bottle on mist works, but a hand held, hand pump, pressurized sprayer works best), and to cloth covered seats whenever static raises its ugly head. I rather suspect the following - If the floor is concrete and the chairs wood you should be OK.
One note, I have found lately and that is...all dryer sheets are not created equal. I found one brand that does not stop static no matter what. I think they would cling together if you placed a complete box in the dryer with nothing else, so based on this, be careful in your choice of liquid softeners.
