I need to make a French sign that says:

“Please do not flush anything other than toilet paper (in the toilet bowl)”

Here is the translation. papier hygiénique. Toilet paper in French, is papier hygiénique.

The entire phrase, Please do not flush anything other than toilet paper in the toilet bowl, translated into French, is:
s’il vous plaît ne pas rincer rien d’autres que le papier toilette dans la cuvette des toilettes.

If you have a different way of saying this, please leave a comment.