oil. The only oil I could readily find at my Mother-In-Law's was olive oil, so I put a small amount onto a couple of pieces of kitchen roll and rubbed the sea glass over the patches of oil. And, once dry.... voila!

Filling a spray bottle with some undiluted white vinegar is a great, fuss-free way to clean windows. Working your way from the top of the glass to the bottom, saturate the whole window surface with the vinegar. Once the window is covered, let it rest for 5-10 minutes so the vinegar has time to dissolve the salt scum.

Mix equal parts white vinegar and water in a bucket (you can also make it in a spray bottle). Optional: add a few drops of dish soap to help cut through grease and grime. Use a dry microfiber cloth to remove dust or dirt from the window surfaces.