Hi Tony, I would recommend using a 3 x 2 mtr ext pole, little waffle microfiber glass and mirror cloths, 750 ml trigger spray bottle of Beyond-kleen all-in-one kleen,shine,and protector for glass, 30cm flat aluminum mop frame with velcro strips. remove the black end cone from the ext pole, the shaft on the 30cm mop frame will squeeze tightly onto the pole, then use one little waffle cloth damp with water which will stick onto the velcro strips spray some Beyond-kleen onto the damp little waffle cloth and proceed to wash the glass at what ever height required, when panel is cleaned then take off the damp little waffle cloth and stick on a dry little waffle cloth to polish off for a perfect streak free finish everytime. do this panel by panel and guaranteed you will achieve the perfect finish with no mess as you are just using damp little waffle cloths which are the highest performance microfiber cloths available on the market for cleaning glass and mirrors. Also Beyond-kleen which is based on nano technology contains no IPA,ammonia,solvents,etc, and not only cleans streak free but will leave behind an invisible coating which will make it easier for you to maintain your clients glass for future cleaning, little waffle microfiber glass and mirror cloths are extremely durable and can be laundered up to 800 times, if i can be of any further assistance Tony, just let me know.