No or only very few petrol stations have buckets with (soapy) water, a sponge and a squeegee for cleaning the windscreen. In Germany, every petrol station has them, several of them, usual one between every two pumps. It might even be a legal requirement as an insect-encrusted or be-birdshat windscreen is a safety hazard.
Also, on the continent, you can lock the pumping lever on the nozzle in position so while your tank is filling up, you can clean your windscreen, check the tyre pressure etc. It automatically unlocks when the pump stops when the fuel level reaches the nozzle. Here, you not only have to keep the lever pressed but also breathe in the fumes (in most other EU countries you have a system that catches the fumes (it sits flush on the tank) and pumps them back into the storage tank.