I put the cubes in a little bowl and set it down for him to get them out.
He loved holding them and then letting them go. What a great sensory activity for him and I wasn't even trying to add learning to the bath it just happened. He gets to learn that ice is cold and will melt in the water:-) Also these cubes smell good and have bright colors.
Of course he had to taste the cube. After all it smelled like food. I let him play with the cubes before we did washing. So to me the water was clean enough and so were the cubes.
Hope you can have some tub time fun with your kids too.
Please do come and visit us again. We would love to have you back:-)