I hear from a friend that a number of grower have had trees killed or badly damaged when grown in catlitter after the chemicals used were changed. I have been trying to find the article but have been unable to.
I wonder if anyone has seen this mentioned anywhere?

Nope, haven't heard of it. You've heard it from a friend who has heard it from... so your topic title isn't OK.

It is for that reason that some people chuck the bag of clay pellets in a container of water for a few days, rinsing once a day. To get all types of solubles out. I normally don't. I ave not had this type of trouble.

It's a hell of a lot of trouble to have to go to to make it safe. I have still not been able to find the refference, but when I do I will post.

m5eaygeoff wrote: It's a hell of a lot of trouble to have to go to to make it safe

Seems you missed the "I don't" part - and I don't see why it is a "hell of a lot of trouble". I do put my baked clay pellets in a plastic container filled with water, but that's just to rinse of some of the dust.
No one here said that using it is unsafe, but seems you are trying to prove a point - without giving any reference.

Used, cat litter would not be advisable, it smells funny. If you look real hard, you'd find people, finding something wrong with anything. If it works for you, great. rinsing the dust out does make since though. Maybe i'll try that, then again.