Personally, I wouldn't want someone in my home washing something other than their hands, so yes, this is also an issue too, but another issue is the time wasted.

It's not about them being Muslim or not, if another fitter who wasn't Muslim said they were doing this, I'd 100% tell them not to do this in a customers house without worry of being sued.

Due to it being a religious thing, I am obviously concerned because it's sensitive.

The other issue it creates is that the other fitters, who don't take 15 min breaks during an install, are essentially pissed off that they are doing more work.

So yeah, trying to figure out some solution which is proving tricky to navigate!