The cringeworthy gold greeting is the best time to ask for stuff that I don't have in the cabin class that I am flying in.

I usually request for Slippers while travelling in J.

I dont think that I have ever been refused as they have just told me that ' If there is anything I can do to make your travel more comfortable then please let me know'

Always be polite and ask for one if they have any spare one's. I used to carry my own ones but don't travel that often in F nowadays and have run out . :-(