There. I've said it.
And the reason is simple:
Once a mitt/sponge is dirty it's never clean until it's completely washed out, and the minute it goes into the bucket now the bucket-water is dirty.
Much better for homes with water:
(1.) Spray your car down
(2.) Spray on shampoo with a hose foamer or a hand spray foamer like a Marolex
(3.) After a dwell, use 1 rag/sponge/mitt per panel working top down and then flip to a clean side until all sponge/mitt sides are used - then put in a dirty pile & grab a new clean one.
This way, no using the same dirty sponge/mitt/rag on more than 1 panel, and no contamination of wash water, not to mention WAY less hassle, water, & mess
And
this method is easily adaptable anywhere, even without access to running water - like say if you live in an apartment or are on a road trip and just drove through bugs:
*> Spray down the car at a u-wash if you can (or use
a battery power sprayer) or pre-spray with
rinseless wash like Mckee's 37
*> Put 1/2 gallon of distilled water in
a collapsible bucket with a cap of Mckee's RW and, say, 4
Rag Co Everest 550 MFs
*> Put some Mckees RW solution into
the marolex if you haven't already
*> Spray down a panel with rinseless wash, and the next panel ahead to dwell; grab a MF/Mitt from the bucket & lightly wring out until just barely not dripping - never put a dirty rag/mitt back into the bucket! Once it comes out, it's out forever.
*> Use 1/4 of an MF or 1 side of a mitt per panel to wash
lightly in one direction* like R to L & work top to bottom, buff dry with 1/4 dry MF until done.
*> Optionally use, say,
TW's Flex Wax as a drying aid
*Why one direction?
Because if you do get scratches they'll only be in one direction so (a.) you can see how well you're doing the technique since you'll know they're yours, but (b.) one direction scratches are very easy to buff out, even by hand.
* Why work top to bottom?
Because the top is cleaner than the bottom so you minimize scratches - ideally do the top 3/4 with one MF and the bottom with a separate one and dump. Yeah, this requires / uses a lot of MFs, but the more clean MFs you use, the lower the probability of scratching.