Squealing steering column.

My stearing column has had a terrible squealing problem. I had read on here to spray in the boot at the fire wall with white lithium grease. I have done that twice and it works great but after about two days it starts squealing again.
Any ideas on something else to spray that would work better?

Ive always just hosed it down with wd40 from both sides. I try to get the straw inside the boot from the cabin side and spray it. I usually have to spray mone once a year when the tempurature starts to drop.