They may be little, but these bad boys pack a punch!
Put one of these menthol steamers in a part of your shower behind you as you shower. You don't need to let it get blasted with water, just a little trickle. Let the menthol vaporize with the steam to open your sinuses up.
Once you've hit your menthol limit, just take it out of the water and set it aside on the tub. Each tab is good for 3-4 showers, depending on how much menthol you like.
I don't recommend using these with little kids, until you know if they have any breathing issues. Also, do not use in the bath tub! Your bits will not like you!