sea foam

Okay so for the past two months I've been struggling to find what is causing my secondary air pump codes. I have replaced the vacuum line that runs from the check valve to the plastic line. That did nothing. I have tried the sea foam trick where you pour sea foam into the hose off the secondary...

I have read posts and seen DIY's on using Sea Foam to clean out your engine... and wonder: Is this a recomended/usefull practice? How many do this? have done/tried this? Does it actually work? What are the benifits? Is it harmless? Thanks