Sand tray for writing

A younger student has been practising writing in the sand tray. Instead of sand I used salt and I think that it gives a cleaner look [perhaps because most of the furniture in my class is white]. This child does not yet like to write, colour, draw or use writing instruments. He really enjoyed writing in the salt tray and worked with this activity for a good 20mins going through every letter that he knew. It is important that the child feels the sandpaper letter correctly before tracing it in the salt/sand. When I present this activity I feel the sandpaper letter 3 times and then trace the letter in the sand/salt.