Oh my god!!! :(

[babydom]

I'd say, "due to recent findings in my washroom, multiple service calls for the toilet to be fixed and constant disinfecting, my washroom will now ONLY be available to the children during daycare hours. Should you or your older children need a washroom, there is a restaurant across the street. Sorry for the inconvenience but I thank you in advance for understanding the predicament I am in"

I like that wording. I'd say the same