98 accord V6 intake port question

Greetings to all,
I have a 98 Accord EX V6. Had the intake ports cleaned and bored out per the
TSB at ~45,000 miles, no charge. Well...at 88,500 the check engine light
went on again, and the code was related to the intake ports (again) and the
EGR. I spoke to the tech himself who seemed very knowledgeable, said this
happens commonly at ~90k miles. Ports cleaned and EGR replaced to the tune
of $265.
My question to the forum is: do any of those after market "valve cleaners"
etc reduce the frequency of this port clogging that is inherent in the
Accord V6 engines. If so, then what products are good?/
Thanks!!
Matthew