In a classroom run show and tell, with a different child each week. Each week ensure the object is not seen before show and tell.
The child “showing” the object can see, everyone else has to be blindfolded. Let everyone feel the object and smell/hear it.
Then hide the object in the classroom and remove blindfolds, can the object be found.
In a class school jumper make good blindfolds.
Or you could bring the object for show and tell and hide it until you have securely blindfolded everyone