We can handle this with a bit more tact, though that might not be the intention it seems to be the result, calling somebody retarded is not really a nice thing to do, or appropriate
We can say what we need to say with a bit more respect.
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I have never used Seafoam or other similar products so I do not know the composition. But, since it must be a detergent or solvent or a combination of them or something similar there would be the possibility of it upon entering the combustion chamber of it washing down the oil film on the cylinder walls and rings and perhaps some could get into the oil, that is pretty simple logically but it might be so diluted it simple is not an issue.
It was a good question, as most are, a good answer is inherently more valuable to our community.