Question to the Rabbi Maran Shlita regarding soft items that are suitable for washing

Ita in the G.M. (Zebachim 17:1) from the words "And the garment, etc. or the vessel of leather which you wash," we learn that leather has a washing. And its washing is by rubbing. And the Interpreter (ibid. 2): Like rubbing, rubbing one side against the other, like the way one washes clothes, holding the garment with both hands and rubbing, etc. Similarly, ita in the Shulchan Aruch (Si. Shev, 9) it is permissible to put water on it, but it is forbidden to wash it, meaning that one side rubs against the other. And in the Bi'al (D. 7:7) he added daf if one does not rub against the other, but rather thoroughly rinses the dirty area with water and washes it so that it is clean, since in general it is rubbing.
And it is explained in the Gamma (ibid.) that soft leathers are worthy of washing, and hard leathers, according to the Rabbis, are not worthy of washing. Therefore, the fact that they are soft is the reason they are worthy of washing, and so the interpretation in the Matani states that there is washing in a pillow, since only soft pillows and covers are not included in the Mimar, so washing in soft leathers is not included. And this is also what the Meiri wrote (Beitza 18:5 in Tractate Zevahim).
And from this we can also learn about other materials found in our time, plastic, etc., that if they are soft, they are considered suitable for washing. And the definition of "soft" is, according to the aforementioned Rashi's commentary, that in the way the clothes washer holds the garment with both hands and rubs its sides against each other. That is, in a soft thing that involves the reality of rubbing its sides against each other, which is the essence of the washing method, it is in the Torah of washing. And washing is considered appropriate from the Torah for anything that has softness to such an extent (and in the Agrom Yod Chab 38, and in the commentary to Chab 69).
And even a vessel whose shape is stable, if it is soft as above, must be considered to have a wash, since a shoe made of soft leather is explained in the G.M. and Shulchan Aruch as having a wash, and as above.
And we must discuss with Paz a 'disposable' cup or plate that is soft and only because the rim is hard, it is not possible to rub side to side, whether they can be washed by rubbing the dirty area with water. And likewise a 'pacifier' and a baby bottle nipple, all the like. And also soft 'foil' and aluminum utensils.
And the Rishonim differed in hard leather, and the court (see 6:9, 15, but not washing) held that the Riff Maimonides, the Rosh and the Tur, were of the opinion that it is forbidden by the rabbis. However, the opinion of Rashi and the Ran, who even considered the prohibition of the rabbis, is the same. And the opinion of the Sheilatut, who ruled as others, is that it is forbidden by the Torah. And the commentary there concludes that the halakha should not be lenient, because all the aforementioned Rishonim were silent on the prohibition and did not distinguish between soft and hard. And according to the rabbinical court, one should discuss, as stated, cleaning plastic utensils, even hard ones, if one can rub them vigorously.