Cheapest is the 2 bucket wash and another bucket with demonshine made up and used as rinse and rinse aid in one.
Applied by watering can or jug.
The O.N.R. is an incredible product...
My Review here...
http://www.the75andztclub.co.uk/foru...d.php?t=105894
There is a More Expensive Option the Nomad 18V washer...
My Review Here...
http://www.detailingworld.co.uk/foru...77#post3405177