I've found that the excessive amounts of lube are a bi-product of people being impatient in sex. Lube is a substitute for going slow, like you should actually do with anal sex.
How slow should you go? SAFETY SNAIL SLOW!
Source:
http://www.ohjoysextoy.com/buttsex/I know for me and basically every anal sex partner I've been with, we all have a strong preference for minimal (and sometimes even no lube, depending on the amount of precum being produced that night) anally. Like, maybe a dime sized amount of lube.
But at the same time, it's worth mentioning that me and every anal sex partner I've had has considered it acceptable for it to take 3-5 minutes from first anal contact to first complete anal penetration. SAFETY SNAIL SLOW. And we spend the time kissing and touching each other, and being intimate. Then by the time you've completed the first complete anal penetration, you've started to significantly lube the anus with precum. And as long as you continue slow for a little while longer, eventually it'll become fully lubricated from precum where you really don't even have to go slow anymore if you don't want.
And that feels a lot better than some sloppy wet overlubed anus. Plus precum is, in my opinion, the highest quality lubricant that feels the best inside of me. I haven't encountered an artificial lube that has yet to meet the same quality standard.
Not that slow isn't almost universally better for the receiving partner, whether you're talking anal or vaginal sex. It's one of the reasons I like anal sex, because it's easier to convince a partner to take it slow for anal sex than it is to convince them to go slow for vaginal sex. (it's also the reason I prefer uncircumcised partners when possible, as they self-lubricate their penis far more successfully than circumcised people do, and for some reason I can't explain, almost unanimously thrust slower and more controlled. I haven't figured out yet why circumcised people seem to thrust frantically, and have to fight consciously to slow down to a more sensual pace. Not that this can't be worked around with circumcised partners, it just takes a more conscientious partner)