There is nothing wrong with a removable sleeve toy. I in fact enjoy the removable sleeves because you can take them off and still have the toy. For some toys you can even buy different sleeves although there are some where you cannot take off or you will mess up the toy.
Sometimes the removable sleeves or any kind of silicone or rubber toy will collect dirt, dust, lent, hair and other stuff too. You can clean it and clean it over and over it still happens just being laid down on something or rubbed against anything. It just happen because of what they are made of. The only way to stop this is stick it back in the box but sometimes that does not help either. So it's best to clean the inside and outside of them before each use so that this does not happen or you get something in your vagina and it will hurt. Feminine wipes can also wipe some of this off too depending on the toy and the wipes itself.
Once you try cleaning them in rubbing alcohol that should take some off the sticky attraction material off in which it also sanitizes the toy just like cleaning them does. There is also a type of powder you can get for them that can help this also.
