For what it's worth, SeaFoam consists(according to their MSDS sheet) of 40-60% of pale oil(mineral oil), 25-35% naptha(lighter fluid) and 10-20% Isopropyl alcohol(Heet) by weight.
I'm with Ricky on this--give it a try and make your own decision.
I will say this--from my experience in a Lawnboy/Toro shop, Seafoam does have at least one benefit. I've resurrected several old two stroke LawnBoys that suffered from low compression due to carbon locked rings. The procedure was to remove the plug, get the piston on the compression stroke about an inch from the top of it's stroke, fill the cylinder with SeaFoam, replace the plug, set the unit up on end(plug down), then pull gently on the recoil in order to force some SeaFoam up into the ring area. Let the unit set for two or three days, pulling on the recoil a couple of times a day. It's certainly not a cure all, but I did see quite noticeable increases in compression in most of these attempts.
Is it the magic elixer? No. Would something else have worked as well? Probably.
As a result of that experience, I run straight SeaFoam through the intake of most all stuff(3 or 4 minutes) that goes through my shop, particularly two stroke equipment. Can't tell you whether it's worth the time and effort to do so. It certainly not going to hurt anything if it doesn't.