Will Ubik stain leaded windows?

Hi, I have a new customer that has a very large house on a main road. Their windows are covered with filth from the road. In the past on first cleans I have had great results by spraying Ubik into my brush and scrubbing with it, then rinsing off as normal. This has worked particularly well on anything near a main road. The only problem. I have is that this customer has leaded windows, and I am just worried that the Ubik will maybe stain the lead. Does anyone have any experience with this?

Any advice would be appreciated.

There shouldn't be an issue as a diluted mix in a spray bottle then spray on brush quick scrub and rinse as you would normally 

We don’t use ubik we use virosol if used-neat that will mark lead , but if diluted 10-1 it’s fine I would say dilute it like that and it should be ok , try a small test area first if in doubt 

Brilliant, thanks for putting my mind at ease.