I've never done anal myself, just doesn't interest me. But obviously, this is a much tighter & less flexible opening than the vaginal one, so from what I've heard, you need a somewhat thicker lube than you'd use for standard intercourse. I'm not aware of any 'natural' lubes that would work for this, maybe others are.
I think the best option is a commercial lube made for that purpose. You said you aren't able to obtain a commercial lube, but you can find them easily from many online retailers. If you have a credit card, you can order from one, just make sure they say they'll ship it in a discreet, unmarked package so no one knows. Most online retailers selling sexually-oriented products state they will ship it unmarked, and often, the item description on your credit card is described in a way that doesn't make it obvious what it is.
Or alternatively, you could ask a friend to obtain some for you, either online or purchased from a a retail outlet. Even WalMart sells all kinds of lubes, including ones for anal use. You can also go thru self-checkout if you don't want a cashier to see what you're purchasing. Hope one of these options works for you...
I agree. That's a sensitive spot and deserves lube made for things to happen easily. I guess to your natural list for creating your own lube, you could add coconut oil.
one diy natural lube is aloe vera gel, that's right right out of a broken aloe vera leaf.