Has anyone tried products like Seafoam for cleaning their valves once the engine is installed?
The catch can and water/meth injection are preventative methods, as stated, not methods for cleaning. And you are correct that there are other threads with this information, but these were worth mentioning here again for others - particularly newbies - who don't know this information has been brought up before.Catch cans and methanol injection have been beaten to death in several other threads. Bottom line is spraying either Seafoam or CRC cleaner through the intake will NOT remove 50k miles worth of buildup. It's more designed as a maintenance item to be used every 10k miles after a thorough initial cleaning. I've done mine twice already. Whether or not it actually does anything, I have no idea. I do know it's super easy to do and relatively cheap so I figure it can't make things worse. There are YouTube videos that show positive results when used in this manner.
Whether you use a catch can, meth injection, valve cleaners, etc there is no cure to the carbon build up that happens with these motors. The best you can do is just delay the inevitable.