I have no answers for you except to remind you that your chemistry is NOT perfect or you wouldn't have organics growing (and smelling) in your pool.
SLAMing the pool correctly results in a sanitized pool that is algae (and smell) free. Maintaining your chemistry at the levels we suggest keeps it that way.
There is no miracle algae (or organics) that can survive a correct SLAM so don't waste your time looking for some other, exotic cause.
Reread the SLAM procedures..........there is an error(s) somewhere in your methods.