Yes. If you have children or animals, its always best to use a liquid treatment which you dilute - keep the animals off till the solution's dry, then after that its okay to let them back on. Also applies to granular feed/weed combinations for grass - use liquid versions and water on. If you're using lawn sand as a treatment for moss, you can buy liquid moss killer solution.

Cheers Bamboo thats a great help, we only moved in three years ago and the lawns where pretty bad, but the moss seems to keep coming. This years plan is to treat the lawn with moss killer and then a good lawn feed hope that does the trick.

A bit of aeration and scarifying in the autumn should help too, though if your lawn is in a shady area, moss will always be a problem.