Professional sales letter to hotels to get them to try my services of grout re colori

My business is in making tiled areas look new and I want to branch out into hotels. In he world of trip advisor hotels are let down by the cleanliness of there bathroomshould and mostly discolouration of grout and mouldy silicone. I can change that in a day with specialist cleaning of grout then re colouring in the same colour of a completely different colour with 10 to choose from. All for a fraction of cost of retiling. I need a sales letter to get me in to show off my services.