I use 2 buckets to wash the car then soak up the rinse water with microfiber towels. I have bought some from outdoor gear places and they absorb the water very well. I have seen people claiming to use distilled/deionised water for a rinse
www.detailingworld.com)or rainwater from a collecting butt.I also use an air blower to blow out crevices round beading etc. especially prior to the waxing. I only wax about 3 times a year with a clay session included.