BB's are steel so that's a non starter for the corrosion issues that they will cause.
Pellet weights work well on off road rigs for all of the reasons listed by chromag.
I have run them for many years on my dedicated off road tires.
I run lead on my DD skins though.
i feel zuks can get away with unbalanced tires better than heavy rigs, but thats not been proven.
Don't you believe it. Short wheel base light rigs are much more susceptible to un balanced tires causing poor to disastrous driving conditions.......