[pikevi]

I don't know if there is a specific way to treat/sterilize cholla, which seems like a member of the cactus family.

I usually immerse the whole log in water for a day or two in order to get rid of the worms/insects that are borers. Then I wash it with 'hot' water and dry it under the hot sun. (I don't know what can be done in winter!).

[you could also spray it with safer's soap or something similar but I have never done it]

I have not had any problems with any insects.

I ,however, am not sure if it is the right thing to do with cholla.

Good luck.