Yes, bad rumor... The seeds contain no heat. It is the ribs that the seeds attach to that contain most of the heat. If a seed is hot, it us only because it got some oil from the ribs on it.
I would suggest against using pure capsasium btw... If you must, look up a more suitable product such as pure evil drops. I think they rate at 9.6m shu, and the weaker version rates at about 1.5m shu. Still, even a few drops of 9.6 could overpower a batch for most people.
I suggest processing raw peppers as posted above. Dried peppers would probably work even better. If you want some real heat, use habaneros instead. Skip jalapenos and serranos. For a 5g batch, I am sure you would need a lot to get any real heat. Even better, try to find someone who grows a lot of peppers. I would stay away from superhots at first. Some good choices for flavor and heat would be Bahamian goats, Scotch bonnets, Fataliis, Aji cito, Aji limon, Chocolate habaneros. There are a bunch more, but those are all among the most flavorful.