It should be unnecessary for me to say this but it is too important to ignore. I expect all my visitors to meet a very high standard of cleanliness and personal hygiene and failure to do so will result in the session not going ahead.
You should aim to shower or bathe as late as possible before leaving to visit me to ensure these high standards.
Please do not take the view that lower standards of hygiene can be used as an excuse for more punishment. It can't, but it can be used as an excuse for being shown the door.