Oh, my mistake. This is the only option to the BMU that I know of - chair rigging by rope. Here is a link to another short video. Enjoy.
https://www.google.com/search?q=window+cleaning+climbers+high+rise&sca_esv=eab902f88a49963b&rlz=1C5CHFA_enUS1020US1020&sxsrf=ADLYWILwf3sUoURZUn8MEgRa7_6VUiO0fg%3A1728848820902&ei=tCMMZ_XWNpqgiLMP1ZO-6Qw&ved=0ahUKEwj1gNzej4yJAxUaEGIAHdWJL80Q4dUDCBA&uact=5&oq=window+cleaning+climbers+high+rise&gs_lp=Egxnd3Mtd2l6LXNlcnAiIndpbmRvdyBjbGVhbmluZyBjbGltYmVycyBoaWdoIHJpc2UyBRAhGKABMgUQIRigATIFECEYoAEyBRAhGKABMgUQIRirAjIFECEYnwUyBRAhGJ8FSIUjUIsIWPIacAF4AZABAJgBaKABnweqAQM5LjG4AQPIAQD4AQGYAgugAtoHwgIKEAAYsAMY1gQYR8ICCBAAGBYYHhgPwgIGEAAYFhgewgILEAAYgAQYhgMYigXCAggQABiABBiiBJgDAIgGAZAGCJIHAzguM6AHjlk&sclient=gws-wiz-serp#fpstate=ive&vld=cid:f7b17400,vid:XYy-m-Vqrdw,st:0
Also, I am now thinking we need to invent more ‘tilt-in’ type windows that can be cleaned from the inside. No unsightly BMU machines on the roof, and no dangerous chairs being repelled by rope on the side of the buildings.
Like This -
Also - These guys are even better - they don’t use wooden chair. 
BTW - I have a 123 post on this topic. Click on my infoshare tag above to see all links/comment/photos. 