You have to ask why you are only doing it occasionally when ii is the highest rate for any cleaning process ?
http://www.aquafed.co.uk/product-category/gutter-vacuum-systems/3000-watt-gutter-vacuum-systems/Used one these over five years taken loads abuse and good price and spare parts available If you want that size overwise the mini grafter twin turbo good value but aquafed are a really good company to deal ask for mark very helpful
It's the clear plastic one with an orange/blackish grey style head 3000watt I also will be purchasing grippa grafter mini this week. as I can't handle that brut anymore but my subbie uses it fine plus space s im in a ford connect now but at VWT 5I currently use Gardner section clamped #10 carbon poles with grippa attachment at the top Or base modular sections upside down as it doesn't damage them that way