Merrily, Merrily, Merrily
A likes to sing sometimes. I read somewhere once that one way to get your child to wash their hands for a long enough period of time is to have them sing "Row, Row, Row your boat" while they are washing up. I tried teaching A this, and this is now what he sings while washing his hands:
"Row, row, row your boat. Gently stream. Merry, merry, christmas everyone!"