I can guarantee that you will not find a pair of shoes or boots that are safe on slippery roofs.
When climbing around a dry roof it is the friction between your sole and the roof which prevents you from sliding off. When the roof is wet or worse still, there is a layer of slime between your sole and the smooth roof, you have no friction and will eventually fall off!
I would stay off them, tell the punter that you will restart cleaning them when the roof is dry.
This is one of the main reasons why we have so many accidents om the industry, people think they can do things all year round, your own safety must come first.
If you are determined to do them, invest in a WFP, then you can go out wearing whatever footwear you want and still be 100% safe.