If this is really true, why does Gillette advertise their high-end, multi-blade razors as multi-use? For their top product, they say "up to 20 comfortable shaves".
Sure, in this case you usually don't buy a single use razor, just the blades. The blades are sharp enough to use them multiple times, but if you don't want inflammation, then it's recommended to only use them once. Search for Wilkinson Sword blades.