No. There are many cheaply imported ‘ethnic’ ocarinas that cannot be played safely or even in tune. All Ocarina Workshop ocarinas have been tested and certified as safe and Play your Ocarina teaching resources guarantee their effectiveness in the classroom.
Most primary school children prefer the simplicity of the 4-hole Oc® . The first 40 tunes in Play your Ocarina books are just played on the top four holes. A 4-hole ocarina is sufficient for Book 1 and Book 2, and for many of the tunes in Carols and Songs of Praise. If your children are older, are very musical, or want to progress to Book 3 and Book 4, then the thumb-holes of the 6-hole ocarina are useful for the extra notes.
Ideally children should have their own ocarina for lessons. If an ocarina is to be shared between children, you should sterilise it between uses by using a dilute solution of any sterilising liquid suitable for cleaning babies’ feeding bottles. Keep the string away from the solution and make sure the ocarina is thoroughly dried.