Maybe not the best idea.
Care and hygiene. Actually two terms that belong together. With pumice stone and its relatives (lava stone, synthetic corneal sponge, etc.) one should rather not think too intensively about the aspect of hygiene. Because all of them have in common a porous and consequently rough structure.
Where and when is a pumice stone best used again? Oh yes, in the shower or when taking a bath.
And what exactly was an ideal climate for germs and bacteria? Oh, yes, moisture and heat.
The same pattern and unhygienic!
It is a fact that all grinding and reaming tools generally lead to rough skin. This is in their nature. However, with pumice stone and similar materials, they are also difficult to clean.
In addition, unfortunately, the cornea itself is an ideal shelter for germs and bacteria due to its sponge-like structure. Thus, two good friends meet at every treatment. Want a scenario?
First the new pumice stone is rubbed over the heels. It then absorbs the skin mass and the bacteria it contains right down to its deep structures. A short wash of the stone cleans the pumice stone only superficially on closer inspection. Then it lies with its inhabitants at the edge of the tub and together they wait patiently for the next use, making themselves a little bit comfortable in the warm and humid climate. At the next treatment, the user uses the pumice stone again in the tub and shares his bath water with the germs. The idea of sharing this involuntary, shared bath with your partner's bacteria, or with other household members, just when you share a pumice stone, is also very piquant. The game is repeated week after week, and you can cheerfully mix the bacteria in the whole household (assuming they are shared).
Admittedly, slightly ironic and perhaps a little exaggerated. But in essence, that statement is correct. Pumice and colleagues are quite unsanitary and have nothing to do with the understanding of care as seen by Mr. Fuss.