Scented Pastilles

1/2 cup flour (not self-rising)
1/4 cup salt
1/4 tsp. powdered alum (from drug store)
1 Tbsp. essential oil (any scent)
2/3 cup boiling water
Food coloring (optional)

In ceramic or glass bowl, mix dry ingredients thoroughly.  Add essential oil and boiling water.  (Scent will be strong and will fade slightly when dry.)  For colored dough, blend in food coloring, one drop at a time until desired color is achieved.  Blend ingredients to form a ball.  Working with a small amount at a time (approximately 1/8 tsp.), roll dough between palms of hands to form small balls.  Cover unused dough to keep it from drying out.  Allow pastilles to dry.  Display in open baskets or glass containers to add pleasant scent to your rooms.