The pads are glued to the inside of the shirt. It's a bit fiddly, and it may happen that they are not aligned 100% as you want it, that one probably a little too high, so if you still sweat stains are visible.
When it but exactly aufklebt, then there will not stain.
If you want to put on the shirt the next day, you can keep the used pad quietly, it develops no strong odor. But much more often will not use it there. Abwachschbar it should not be, because the adhesive effect should go vcerloren.
