I would try oleander for MS long before I would try colloidal silver.
There can be no promises in this regard, but there is reason to believe (purely theoretical at this point) that the mechanism of action of some of the key components in oleander could be very helpful to people with MS.
On the other hand, I wouldn't take anything that is claimed to boost the immune system unless you know how it works - it could make things a lot worse.
I wouldn't mix NAC with oleander - they seem to antagonize each other.