I mix about one part Chloraseptic to two parts KY in a camera film-canister. Then I use a little plastic syringe to spurt it onto her ring. When it is comfy, I use the lubricity to shove the syringe inside a little and squirt the rest inside. Nice and runny.
Pharmacists are happy to sell this product and never ask screening questions about your rectal health.
If you cannot get a topical anaesthetic by asking that question, as for 'roid ointment as that is often quite lubricative (to ease the chafing of buttocks on severe 'roids).
"Germoloids" is a popular product in the UK but I'm sure there are others.
This can be mixed with KY too, but it isn't as effective - but it is also not green!
I have found that re-applying topical anaesthetic is not usually necessary until the start of the next session. Sometimes she likes to apply pure anaesthetic after I finish inside her, to reduce post-fuck soreness. Once or twice I have had to pull out and apply some more if she is really having trouble taking it, but this is rare.
I have used germoloids a small number of times to reduce her initial pain on entry when introducing a younger lady to first-time anal sex. The less it hurts the first time, the more likely I am to get up her anus the next day (for some reason I find that younger ladies are less enthusiastic about my buttfucking them than more senior ladies are).