Firstly: Using vegetables and fruits for cosmetic purposes is not appropriate, because that is using these blessings for a purpose for which they are not meant. It is also a kind of extravagance and wasting time, and following every fad that comes from cosmetic surgeons and foreign magazines and so on. The believer should set his sights higher and aim to achieve a lofty status in the Hereafter.
It should be noted that the scholars differentiate between using plants for medicinal purposes and using them for cosmetic purposes. Shaykh Ibn ‘Uthaymeen (may Allaah have mercy on him) was asked: Some of my friends use eggs, honey and yoghurt to treat freckles that appear on the face. Is it permissible for them to do that?
It is well known that these things are foods that Allaah has created to nourish the body. If a person needs to use them for any other purpose, such as medical treatment, there is nothing wrong with that, because Allaah says (interpretation of the meaning):
“He it is Who created for you all that is on earth”
The word lakum (“for you”) includes all kinds of usage and benefits, so long as there is nothing to indicate that it is haraam.
With regard to using them for cosmetic purposes, there are substances which may be used for such purposes instead of these, so it better to use those. It should be noted that there is nothing wrong with beautifying oneself, indeed Allaah is Beautiful and loves beauty, but if a person goes to extremes in that so that it becomes his primary concern and he does not care about anything else, and neglects many of his worldly and spiritual interests because of that, this is not right because it comes under the heading of extravagance, and Allaah does not like extravagance.
From Fataawa al-Mar’ah, compiled by Muhammad al-Musnad, p. 238.
There is nothing wrong with bringing these plant products into the bathroom, but staying there for an hour for the purpose of beautification comes under the heading of extravagance, as stated above.
And Allaah knows best.