One type of Mukse is “Basees L’davar Ha’asur”- a base for a Mukse item also becomes Mukse. Even if the Mukse item is subsequently removed, the base remains Mukse, as long as the Mukse item was on it during Ben Hash’mashot (twilight) of Ereb Shabbat. For example, if money was placed on a chair on Friday, the chair becomes Mukse, even if a non-Jew removed the money during Shabbat.
Hacham Ovadia was asked the following question regarding this Halacha: What is the Halacha if the Mukse chair became mixed in with the other identical (non-Mukse) chairs in the house? Does the concept of Bitul (nullification) in the majority apply to Mukse, as it does to meat and milk? Accordingly, if there were a total of three chairs, then the Mukse chair would be Batel (nullified) in the majority of permitted chairs.
However, the principle of Bitul does not apply to “Davar She’Yesh Lo Matirin”-cases in which the forbidden item will later become permitted. The classic case is an egg laid on Yom Tob, which is Mukse of Nolad, that became mixed in one thousand permitted eggs is not Batel, since that egg will become permitted after Yom Tob. Similarly, in the case of the chairs, the Mukse chair will become permitted after Shabbat, and would not be nullified in the mixture.
Nevertheless, the Nodeh B’Yehuda (R. Yechezkel ben Yehuda Landau, 1713-1793, Prague) has the famous opinion that the restriction of “Davar She’Yesh Lo Matirin” applies only to food. His rationale is that food is a one-time use; it’s eaten and then it’s gone. Regarding such items the Halacha requires delaying the one-time consumption to eat it in its permitted state and not while it is still forbidden, since anyway there is only “one shot.” However, something like a chair can be used time and time again. Therefore, the Halacha does not require one to miss out benefiting from it on Shabbat.
Hacham Ovadia is lenient and relies on the Nodeh B’Yehuda in the case of Mukse, which is M’drabanan, and permits using all the chairs.
If a Mukse non-food item became mixed in with identical permitted items, one may rely on the lenient opinion and use all the items on Shabbat.