birdy, if you have a van, get a tank put inside and a 12v submersible pump and just use one 25 litre barrel and refill it each time.
If you can't get a tank put inside then ignore. But this way is soooo much quicker.
Also, to speed you up is getting 10 metre extra hose that goes up the pole. So if you use an 18 ft pole, get 50 ft of pole hose and replace the original hose that has come with the pole.
This will allow you to position the trolley in 1 or 2 places and work from there.
With normal pole hose lengths, you will have to move the trolley every couple of windows and this is very time consuming.
Start at the back of the hose or furthest from the van so if you run out you will have less distance to travel.
If you can get a water tank fitted to your van, you wil have the option of using the trolley independantly or by plugging it into the main tank. With a reel of microbore you will then have a van mount as well.
I believe by just doing the above you will knock 25% of the time you work off your day.
You will then knock more time off per job with experience of the trolley and knowing your work place. But this will take several cleans.
Good luck with the trolley. It's a good bit of kit.