Just finished cleaning a regukar job (every 4wks). Cleaned it for yrs with my friend, whose work it was previously. Cleaned it traditional method. Large farm but ran an accountant company from it. Theres a large farm house with a conservatory full length of house. A granny flat at another end and a block of offices. With 2 of us, traditional it took about 40mins. As soon as i took over, switched it to wfp and by myself can pull up and load bk up within 30mins. However they have all staff cars in, dogs n horses and plenty of foot traffic. Rather than use main hose as a trip hazard (yes i use cones as well), i now whip trolley out. Takes 2 fills, but can use less than 50ltrs of water and just over 30 mins to leave. They have there advantages, even cheapo bkpacks...