WD40 works, but it's messy.

Dry lubes are available. Some are graphite based, which I worry might transfer to clothing. But I may be wrong.

I have tried pencil lead (HB), but there's too much clay and not enough graphite to really help.

I was given a spray lube by Liquid Wrench which deposits a Teflon coating and the carrying spray then evaporates. To be honest, I haven't used it enough to know if it's worthwhile or not.

If somebody knows what's good, I'd like to hear about it too.