Place rice, almonds, and coconut flakes into a food processor. Process until ground to the consistency of sand. Pour rice mixture into a bowl and stir in boiling water. Cover and rest for 6 hours or overnight.
Strain rice mixture through a sieve twice, discarding ground rice, almonds, and coconut. Stir in coconut milk and sweetened condensed milk. Stir in cold water and serve over ice.
